Foil stamping is usually used to decorate printed and souvenir products. You can decorate almost anything this way: from business cards to bags and leather goods. The impression can be applied in several ways, which differ in material and manufacturing technology. You can do gold foil stamping, make a hologram, or even imitate the surface of wood and stone. You can apply drawings not only in special workshops, but with simple equipment, and with your own hands at home. To create an embossed design at home, you may need a laminator or an ordinary iron.

How to apply a design using a laminator

To make a design using a laminator, you will need a laser printer (ideally a simple one, not a full-color one). It is better to use a laminator with the highest compression gain. For this method, a toner-sensitive material is used. You can use glossy, matte and holographic foil. And here It's best to use regular paper. On decorative and textured paper, when embossed with a laminator, patterns may turn out sloppy, since the material may not be fixed in the recesses.

The foiling process using a laminator is as follows:

• Find on the Internet or create a pattern or inscription yourself in an original font (it is better that the lines are thick);
• Print the selected picture;
• Place the printout face up on the table and cover with foil;
• Place another sheet of plain paper on top;
• Pass the resulting “sandwich” through a laminator. If for some reason you are not satisfied with the result (the pattern is intermittent or untidy), repeat the procedure.

To get the impression right the first time, try to remove the material from the product as slowly as possible.

Gallery: gold and silver foiling (25 photos)

Foil stamping at home with an iron

Still, a laminator is a specific thing and not everyone has one. If you don’t have this device, but want to make an original drawing, you can use an iron. The sequence of actions will be exactly the same as if you were working with a laminator, with the difference that the foil must be laid with the wrong (matte) side on the work surface.

Set the iron to low heat. Iron the piece slowly and carefully. If the metal does not stick to the sheet, increase the temperature slightly. You need to iron the drawing for at least two minutes, usually this time is enough.

At the end of the process, let the workpiece cool, and only then carefully remove the material.

Embossing on leather

To emboss leather, in addition to an iron, you will need cliche(stamp with a pattern), you can use, for example, a large metal button.

The process of creating an impression on the skin is as follows:

Removing metal from leather is not so easy, so before you start foil stamping on leather, it is better to practice on unnecessary pieces, calculate how long it will take you to complete each stage, and only then start processing the product.

Embossing printer

If you plan to take impressions regularly, you may want to consider purchasing special printer, which is called so, hot foil stamping printer.

The device does not look exactly like the printers we are used to. The metal film is wound on two printer shafts, on both sides of the working part. Under the rollers there is a foil stamping press, where the “sealing” process takes place. The device connects to the computer via USB.

Only those who plan to do embossing repeatedly should think about purchasing such a printer. After all, this thing is not so easy to find on sale, and it is not cheap.

Naturally, the process of foiling in production differs significantly from manual embossing. And, of course, equipment for industrial embossing is not limited to an iron.

Professional embossing is a type of printing, the only difference being that thin metal is used instead of paint.

As a rule, letterpress printing technology is used to create a print, that is, patterns protrude above the surface of the cliche.

When examined in detail, this process looks like this:

• The printing plate is heated by current to the desired temperature (the temperature is maintained for the required time using a thermostat).
• A strip of multilayer foil is “stretched” across the work surface. In other words, at each working stroke, the metal sheet moves along the pattern at a given distance and is pressed by a press for hot foil stamping.

In fact, the principle of operation of the press is similar to the operation of a home printer. It differs, first of all, in the volume of products produced and the accuracy of settings.

How cliches are made industrially

To work with foil, cliches of increased strength and wear resistance are used. Typically, dies are made of metal, most commonly brass, copper, magnesium and zinc. Magnesium dies are most often used for small batches of products; the most wear-resistant brass dies are used for large batches of products.

I am often asked how to make a cliche for embossing on leather yourself. My answer is that, of course, not everyone can do this. Some skills and abilities are required, such as sculpting or the skills of a model maker or carver. And of course you need a very strong desire.
One of the simplest ways to make stamping clichés yourself is to cast them from low-melting metals. If you have the skills suitable for this business, then it will not be difficult, and in this way you can easily and quickly create a large collection of cliches without much expense.
The casting model is made from sculptural plasticine or wax. I prefer wax, since I create the model by carving with cutters. And from plasticine you need to sculpt, not cut. Well, whoever likes it. The conditions for reproducing small details are also the same for both plasticine and wax. If you don’t have the relevant experience, then it’s better to start with simple models that don’t have particularly small parts. I will not describe how to make a plaster mold and how to pour tin or lead, since this is described in more detail on the internet on sites dedicated to decorative tin casting. In fact, you can cast from lead, especially large products that do not have small parts. Tin is more fluid and plastic in the molten state. which is reflected in the final quality of the product. I also do not recommend making cliches with thin, high relief - since, after all, tin and lead are very soft metals. But the softness of the metal has its advantages, among which the main one is the ability to modify the finished cliche with a needle file, an awl, or a graver. It won't work the first time, but it won't be difficult to learn. On this product, a geographical map is imprinted using a cliche, the image on which can be engraved using an ordinary awl (if there is no other tool), given the softness of tin.
Now about the quality of such cliches. Of course, you shouldn’t compare them with magnesium or brass. But tin or lead cliches are made independently and are very cheap. Therefore, even if their circulation is small, producing several identical ones to replace used cliches in the future is not a problem. For a hundred prints, with careful use, one cliche is quite enough. Cliches cast from zinc are more durable because it is harder and melts at a higher temperature. But I don’t work with zinc due to the fact that it is not so fluid and plastic. And I don't like working with zinc.
It is not so easy to understand all of the above theoretically. Therefore, it is better to try it in practice and solve any difficulties that arise along the way. In the future, I will tell you about some more ways to make your own clichés for embossing on leather.

It’s not often that the average person needs information on how to make their own stamp. But there are still cases when advice of this kind will help in creativity or the implementation of creative ideas. We have put together several recommendations, but first we will look at the types of stamps and their purpose.

There are seals for official documentation:

1. Stamp. Certifies the authenticity of government documents.
2. A commercial. Used individual entrepreneurs And legal entities.
3. Stamp. Replaces handwritten text on institutional letterheads.

If everything is clear with the documents, then how to label your books, letters, personal belongings? Masters accustomed to standards are unlikely to make a creative sketch of an image. It's easier to make an impression yourself. Below we will tell you how to make printing at home.

Attention: the instructions contain tips on how to make a seal for personal needs. Illegal production of a stamp for commercial or other purposes is punishable by forced labor or imprisonment for up to two years. In the best case, you will have to pay a fine of up to 80 thousand rubles. (Article 327, paragraph 1).

Types of homemade prints:

• Bookplate. You can use it to mark, for example, books in your home library. The print may contain a beautiful image or your family crest.
• Logo. They put it on hand-made products, paper bags, packaging.
• Blank for wax impressions. Used to seal letters.
• Toy print for games with children.

Metal impact stamp - another type of homemade impressions

Image creation programs

Making a print begins with creating a design for the print. Graphic programs are used for this:

• Stamp is a popular and free software for creating image layouts. Intuitive, even an inexperienced user can work with it. You can only download the demo version for free.
• "Stamp" is a free program with wide functionality.
• Corel Draw, Illustrator - vector graphic editors for creating detailed images. Requires basic skills.
• Fine Print is a paid program for inserting a print image into a text document.

The process of creating a print layout in Corel Draw

Methods of making seals

Here are 3 main methods: complex, simple, for children.

Complex: photopolymer printing

Photo exposure technology is capable of conveying the smallest details of a drawing. However, it is financially expensive and difficult to implement: you need to master graphics programs, buy film and polymer, find an exposure camera and a suitable laser printer.

Step 1. Need an image layout. To create a professional drawing, use Corel Draw, but other programs are also suitable.

Step 2. To print the layout, use a laser printer with a resolution of 600 dpi. Lomond or Kimoto films are suitable as a base.

Step 3. Straighten the negative and place it face up on the glass. Before doing this, moisten the glass with water so that the negative sticks better. It is advisable to cover it with protective film. Using smoothing movements from the center to the edges, remove air and remaining water from under the film.

Step 4. Cover the edge of the negative with border tape, leaving the corners free.

Step 5. Evenly, without breaking the stream, fill the negative with photopolymer. If bubbles appear, poke them with a needle or blow them out with a stream of air from a rubber bulb.

Step 6. Carefully place the film on the polymer with the rough side inward and the smooth side outward. Press it lightly in the middle and gradually release the ends. Place another piece of glass on top and use clamps (available at office supply stores) to secure it around the edges.

Step 7 Place the resulting “sandwich” in the exposure chamber. The front side should be on top. Set the exposure duration. When the process is complete, turn the composition over and repeat the procedure. Each polymer has its own exposure duration. For example, VX55 and ROEHM should be kept for one minute. To avoid mistakes, read the technical regulations.

Step 8 Carefully remove the glass and separate the negative from the resin. Leave the clear substrate in place. Use a toothbrush and a non-abrasive cleaner to remove any remaining uncured resin from the cliche. It is best to do this under running warm water.

Step 9 Soak the washed cliche in water for 5-10 minutes and re-expose it.

Step 10 Carefully cut out the cliche along the contour without touching the edges. Glue the workpiece onto the equipment. The print is ready!

Beginners often separate the substrate from the polymer after exposure. As a result, it is impossible to glue the stamp blank. Remember: the rough surface of the substrate comes into contact with the polymer, and the smooth surface sticks to the body.

This impression can be used to seal with wax or sealing wax.

Simple: stamp made using foil

Find an old stamp or board of a suitable size, preferably with a handle. Glue the resulting inscription to it, and you can test the quality of the print.

This technology does not require any special artistic talents from you. Materials for making blanks are available in every home. The wear resistance of such a stamp is lower than that of a photopolymer, but with its help you can make several hundred impressions.

Step 1. Choose a suitable drawing. Transfer it to tracing paper and then to foil. To do this, you can take a pencil or a non-writing pen and trace the outline with light pressure. Any foil will do: food foil on a roll or from a chocolate bar.

Step 2. Carefully pour strong putty or epoxy glue into the resulting recesses. Set the workpiece aside for two days to dry.

Step 3. At the end of the period, remove the resulting inscription from the foil. The cast should come off easily.

Step 4. Find an old stamp or board of a suitable size, preferably with a handle. Glue the resulting inscription to it and test the quality of the print. Ready!

The basis may be a worn out rubber stamp

Prints for children

Who among us hasn’t drawn on an eraser and then enthusiastically stamped the last page of the notebook? Children love making prints. And you can make a whole collection of curly stamps with them.

Foil stamping is mainly used to give souvenirs and gifts printing products individuality and originality. They decorate business cards, postcards, folders, notepads, bags, Leather Products etc. There are several methods of printing with foil, differing in the method and material of application. Technologically, embossing is not a particularly complicated procedure. You can decorate any souvenirs in this way even at home.

Foil stamping methods

You can do something like this in two ways:

• using a laminator;
• iron.

How to apply a design using a laminator

To print in this case, you will need, in addition to a laminator, it is better if it is not full-color, but regular. As for the laminator, it is worth purchasing a model with a very high compression force. You will also need tone-sensitive foil. If desired, you can use either matte or glossy, or holographic.

It is best to use plain paper. Textured or special decorative ones for embossing at home are not very suitable. When using such material, the drawing will turn out sloppy and ugly. In the recesses of this type of paper, the metal simply will not stick.

Foil stamping using a laminator is done as follows:

• Find a beautiful vector pattern or ornament. You can also write in some program, for example in Photoshop, a suitable text in the original font. It is only desirable that it not be too thin.
• Print the drawing on a printer.
• Place a sheet of paper with a pattern or message on the table and cover it with metallic foil of any color.
• Place another sheet of clean paper on top of it.
• Pass the resulting “pie” through a laminator. Thin foil will definitely stick to the picture. If the pattern turns out to be sloppy and intermittent, the procedure can be repeated. Run sheets through the laminator until satisfactory results are obtained.

The material must be removed from the sheet carefully, slowly.

Foil stamping at home with an iron

Of course, not every household has a laminator. This device is inexpensive, but it is not necessary to buy it in order to make beautiful embossing. You can also use a regular iron for this purpose. With regard to the inscription or pattern, the procedure in this case will be exactly the same as when embossing with a laminator.

The printed sheet should be placed on a hard surface with the pattern facing up. The foil is placed on it with the wrong side down. That is, the shiny side should be on top.

The iron is set to minimum heat. They need to move them along the foil as carefully as possible. If it does not stick to the pattern, increase the heat setting a little. You need to iron the foil for about 2 minutes until the thin metal sticks to the heated paint. Do not remove the foil from the sheet immediately. Wait until it cools down.

Embossing on leather

Using the technology that will be presented below, you can decorate almost any leather product: bag, boots, wallet, notebook, belt, etc. To complete the design in this case, you will need a cliche - a special stamp with a pattern. You can take, for example, some large metal button. The procedure for foil stamping in this case is as follows:

• The skin is placed on a hard surface.
• A small rectangle is cut from the foil (the size of the future drawing). It needs to be applied to the skin.
• Next, heat the iron and press it onto the foil. You need to keep the hot sole on the material for about a minute.
• After the thin metal has warmed up well, the iron is removed.
• Without waiting for the workpiece to cool, you need to attach a button to it and press down firmly. The “cliché” should be kept on the skin for at least 30 seconds.

Foil stamping on leather at home is a simple procedure, but in any case, it’s still worth practicing on an unnecessary piece of material first. If you underexpose the iron or stamp, the design will turn out sloppy. Removing foil from a bag or wallet will be quite problematic.

Embossing printer

Today, if you wish, you can purchase special electronics for making inscriptions and patterns with thin metal. This is a so-called hot foil stamping printer. It connects directly to the computer via a USB connector. Of course, this device is not very similar to a regular printer. The foil in it is wound on two shafts located on both sides of the working part. Below them is a movable flat solid surface. The device comes with a disk containing software specially designed for printing.

Of course, a foil stamping printer is not cheap. Yes, and buying it is still quite problematic.

Industrial embossing

So, we found out how to decorate souvenirs, things or cards using foil. Now, for general development, let's talk about how embossing is done in an industrial setting. In this case, of course, much more complex, professional equipment is used, for example, a foil stamping press. The procedure itself is carried out in compliance with specially developed technologies.

In fact, foil stamping is nothing more than a type of printing. The only peculiarity is that the drawing or inscription is applied using thin metal rather than paint. When embossing in this case, the letterpress method is usually used. This means that those parts that are directly responsible for the pattern itself protrude above the surface of the cliche stamp. The industrial stamping procedure is performed as follows:

• The printing plate is heated using electricity. The required temperature is maintained using a thermostat.
• With each working stroke, a strip of multilayer foil, designed specifically for embossing, moves a specified distance. This process is called pulling.

That is, when using such serious equipment as a foil stamping press, the procedure for applying a pattern is carried out approximately according to the same principle as when using a printer.

How to make a cliche for embossing using an industrial method

Foil stamping technology involves the use of special wear-resistant and durable stamps. Cliches for such decoration can also be made in different ways and from different metals. The design is applied to the surface either by mechanical engraving or chemical etching. Clichés are usually made from metals such as brass, magnesium, copper and zinc. Most often the first two materials. Magnesium clichés are used if stamping is not required for a very large batch of products. The wear resistance of such dies is not particularly high.

Brass foil stamping dies are used for processing large quantity products. Copper and zinc are rarely used, which is mainly due to environmental problems.

Types of foil used for industrial stamping

When applying printing, enterprises use a variety of materials. It could be foil:

• Metallized. This is a well-known shiny material: golden, silver, bronze. Using such foil, you can create both concave and convex patterns.
• Pigmented. After embossing, this variety looks like ordinary paint.
• Transparent varnish. This type of material is used to emboss matte surfaces. After its application, a spectacular shiny pattern remains on the product.
• Texture. This foil can imitate different materials: wood, leather, stone, etc.
• one of the most interesting types of material. Holographic foil stamping is performed, for example, on banknotes to prevent counterfeiting.
• Scratch foil. This type is used to temporarily protect information from being read.
• Diffraction foil. Used for printing on plastic.
• Magnetic. Used in the manufacture of credit cards.

Material for cold and hot stamping

All foil can be divided into two main types:

• Designed for cold stamping. Using this foil, you can print on products that cannot withstand elevated temperatures. Typically these are thin films intended for the manufacture of bags and packaging. The advantageous difference between a procedure such as cold foil stamping and the “hot” method is that this method can produce designs with halftones.
• Designed for hot stamping. This variety is used most often in industry. The types discussed above belong specifically to this group.

Using foil stamping, you can apply patterns, logos, drawings, advertising and greeting inscriptions, panels, etc. to products. The technology for performing such printing is simple, and the procedure itself is characterized by low cost.

Technology for making clichés for hot foil stamping, types of stamping, review of equipment and methods for making clichés

Recently, the number of goods offered in our stores has been increasing and diversifying, which leads to increased competition between their manufacturers.

One of the most common methods of attracting buyer attention to your product is to decorate its packaging or label. There are a lot of printing methods for making beautiful packaging. This includes the design of the packaging shape, the use of special printing inks, embossing (flat and embossed), the application of holograms (holograms also serve the function of protecting goods from counterfeiting), thermography, the combination of different printing methods on one package and other printing methods.

Embossing is one of the most common methods of decorating packaging and labels. Embossing technology is also used in the post-printing processing of book covers, postcards, calendars, in the manufacture of labels and stripes on clothing (chevrons) and in other cases.

Embossing is divided into hot stamping, blind stamping and relief stamping.

is a process of thermal transfer of metallized powder and (or) pigment (colored powder) from a special foil to a printed (embossed) material using a convex metal or polymer cliche.

Hot stamping foil consists of the following layers:
1. Polyester base - all other layers of foil are attached to it.
2. Thermally destructible adhesive layer - when the foil is heated using a cliche, this layer is destroyed (melts and evaporates), thus freeing all the lower layers of the foil from being bound to the polyester base.
3. Paint (pigment) layer - a layer of paint or varnish of the color we need (for metallized foils a translucent varnish is used).
4. Metallized layer (present only on metallized foils) – a thin layer of aluminum that gives the foil a metallic sheen.
5. Hot-melt adhesive layer is a layer of glue designed for gluing ink and metallized layers to the printed material.

Under the influence of a heated cliché, the thermally degradable layer (2) is destroyed, freeing the remaining (color) layers from their connection with the polyester base. Due to heating, the hot-melt adhesive layer (5) sticks together with the ink layers (layers 3 and 4) to the embossed material.
The temperature of the cliche during embossing should be such that, on the one hand, the thermally degradable layer has already collapsed, but, on the other hand, the temperature of the cliche should not destroy layers 3 and 4 glued to the printed material and the printed material itself, and the hot-melt adhesive layer is sticky enough for of this material.
The embossing temperature is usually selected experimentally depending on the properties of the foil and embossed material, as well as the embossing speed and thermal transfer coefficient of the cliche material.

Blind (blind) embossing- This is a process similar to hot stamping, but without the use of foil (which is why it is called blind stamping). Blind embossing is carried out using both hot cliches and cold cliches, depending on the properties of the embossed material.

Embossing is a process of hot foil stamping or blind embossing to produce a multi-level relief image.
Embossing is carried out using two cliches: a matrix - a concave metal cliche and a counter-matrix (matrix) - a plastic convex shape corresponding to the matrix, but taking into account the thickness of the printed material.
Sometimes hot foil stamping is done in two passes: in one pass, flat hot foil stamping is performed, and in the other, blind stamping (this operation simplifies the production of clichés, but increases the cost of production due to double the embossing time).

The basis for any type of embossing is the cliche, and it directly affects the quality of the embossing and, as a consequence, the quality of the final embossed product.

Made from the following materials:

1) Photopolymer clichés: circulations up to 1 thousand prints - usually this is a cliche for the production of small runs of souvenirs and business cards.
2) Metal clichés: zinc (circulations up to 10 thousand impressions), copper (up to 50-100 thousand impressions), copper and brass (500-1000 thousand impressions) and steel (more than 1 million impressions - rarely used).
3) circulation of 100 thousand prints - used for embossing on soft plates (plastic tubes for toothpaste, cosmetics, etc.).

PHOTOPOLYMER CLICHES.

Photopolymer cliches for hot stamping are usually made on specialized equipment, including illumination, washing and drying devices.
Photopolymer plates - blanks are a photopolymer applied to a metal substrate and protected from light with a protective film.

Manufacturing technology of photopolymer clichés

The technology for manufacturing photopolymer cliches for hot stamping is as follows:
1. Preparation of the workpiece. A blank the size of the future cliche is cut out from the original photopolymer plate.
2. Illumination of the workpiece. The workpiece is illuminated through the original film on an illumination device. Illumination ensures polymerization of the polymer in the areas of exposure and, consequently, its fixation (hardening).
The illumination device for photopolymer molds consists of a vacuum table covered with a matte vacuum film on top.
Above the vacuum table there is a row of “daylight” UV lamps with a power of 40-80 W each.
3. Washing out the unexposed photopolymer from the workpiece. The plate is fixed on the working table of the washing device and the unexposed photopolymer is washed out in a slightly alkaline solution.
The washing device consists of a work table with a sheet of magnetic rubber on it and a metal bath with washing brushes attached to its bottom.
A work table with a photopolymer blank magnetized to it (or secured with double-sided tape) produces slow rotational movements along the surface of the brushes.
Brushes remove unexposed photopolymer from the surface of the plate.
At the end of the washing process, we obtain the cliche relief we need on the photopolymer plate.
4. Drying. As a result of the washing process, we obtained a cliche for hot stamping from a photopolymer plate, but the plate absorbed the washing solutions. To dry the plate (remove excess moisture from the polymer), we need a drying operation.
Drying is carried out on special drying trays in a drying unit.
During the drying process, the remaining leaching solution is removed from the plate, and the photopolymer cliche acquires its real size.
5. Final exposure. In the process of illuminating the workpiece with a cliché, the exposure time of the photopolymer is not enough for its complete polymerization.
It only partially polymerizes to allow the unexposed photopolymer to be washed out.
This is due to the fact that it takes a long time to fully cure, which can lead to overexposure.
Therefore, the exposure time of the photopolymer is strictly regulated.
The final polymerization of the plate is carried out in the illumination module without the use of the original film. The plate is illuminated until the process of polymerization of the photopolymer (hardening) is complete. After final exposure, the photopolymer cliche is ready for use.

Equipment for the production of photopolymer clichés

Equipment for the production of photopolymer cliches for hot stamping is usually distinguished by the maximum format of the forms produced and the number of functions combined in one structural module. The most common are monoblock designs (all functions in one housing) and two-block designs (washing machine + light-drying machine).

Monoblock designs are the easiest to operate and cheapest devices with formats from 15*20 cm to 68*86 cm (there are sizes up to 70*100 cm, but this is rather an exception to the rule).
All operations in monoblocks are controlled independently of each other: you can produce up to 3 wafers in parallel, located in different parts of the monoblock at different stages of the technological process.
The main advantages of monoblocks are their compactness, ease of operation and low cost.
The main disadvantage of monoblock structures is the mutual influence of the blocks on each other.
Thus, the operating lamps of the illumination module emit ozone, the washing unit emits harmful fumes from solutions, and the drying device heats all the elements of the machine - all this slowly destroys all parts of the machine.
Most monoblocks allow you to produce photopolymer cliches for hot stamping and embossing good quality.

Single-operation and two-operation blocks for the production of photopolymer clichés make it possible to get rid of the main disadvantage of monoblock machines - the mutual destructive effect of the sections on each other. But at the same time, they require more space for their installation and are more expensive.

Typically, separate blocks for the production of photopolymer forms are high-quality, expensive equipment with a format of up to 130*100 cm and larger.
Using such equipment, it is possible to produce both cliches for hot and blind stamping, as well as raster letterpress forms of the highest quality.

METAL CLICHES

The main metals for making cliches are magnesium, zinc, copper and brass. Sometimes they are embossed with steel cliches. For the production of metal cliches, two main methods are used: chemical (etching) and mechanical (hand or machine milling).
Most of the cliches for hot stamping are made using a chemical method - etching metal plates.

Chemical method for making metal cliches (cliché etching).

This method is most popular when making clichés from magnesium, zinc and copper.
Etching of brass and steel is also possible, but it is used only when etching to a small depth (approximately 0.3 mm), because these chemical processes have not yet been fully studied and the quality of etching of these metals leaves much to be desired.

Plates for making clichés by etching are most often supplied cold (with a layer of photoresist) and consist of the following layers:

Front (working) side
- a layer of black protective film
- photoresist layer
- metal
- a layer of protective paint
- reverse side (base)

Layers of a hardened metal plate for making cliches for hot stamping by etching:

1. A layer of black opaque polyethylene film that protects the photoresist layer (layer 2) from both light and mechanical influences.
2. Photoresist layer - a layer of opaque photopolymer that polymerizes under the influence of UV light and is resistant to weak acids after polymerization.
Photoresist is used as a matrix when etching metal (layer 3).
3. The metal layer is actually a blank for making cliches.
4. Protective paint layer - a layer of acid-resistant paint (usually dark green) designed to protect the base of the plate from being etched during the cliche etching process.

Plates without feeling are also available. They lack a photoresist layer.
From such plates you can make cliches by etching (applying photoresist yourself) or by engraving.

Etching of magnesium and zinc plates

The methods for etching magnesium and zinc plates are very similar: the same equipment and a solution of the same acid (nitric) are used. The difference in technology consists only in the difference in additives to the acid. Recently, zinc pickling has almost become a thing of the past.
The fact of avoiding working with zinc clichés is associated with their low circulation resistance (up to 10 thousand impressions compared to 50 thousand impressions for magnesium clichés) and with the great harmfulness of working with zinc for the human body (heavy metal).

Equipment for the production of magnesium and zinc cliches.

As mentioned above, the same equipment is used for etching magnesium and zinc.
These etching machines are made from of stainless steel and plastics and consist of an etching bath and a control panel. In the etching bath, the working solution is poured onto the plate being processed.
According to the method of throwing the solution onto the plate, all etching machines are divided into blade and nozzle.
In the bathtub of a blade-type etching machine there are shafts with blades. The blades are immersed in the working (etching) solution for several centimeters.
In operating mode, the shafts rotate and throw the solution onto the plate being processed using blades.
The pickling bath also contains devices for maintaining operating temperature etching solution: temperature sensor, heating element and cooling coil.
In some models of etching machines, a circulating solution is installed at the bottom of the etching bath to mix the working solution, but whether it is necessary is a moot point, because it affects the quality of the magnesium cliche only indirectly and not significantly (due to the circulation of the solution, it can be filtered from possible contaminants).

Blade etching machines include STOMA (Germany), Ultramatic and MAG (Italian manufacturers), as well as several American and English-made machines.
In terms of price/quality, the most interesting machines are the Italian machines of the Ultramatic series (the price of the machine starts from $11 thousand with a machine format of 40*50 cm), because the German Stoma machine is much more expensive (despite the same quality of the resulting cliches).
The MAG series machines are slightly inferior in design to the Stoma and Ultramatic machines, but with the high professionalism of the etcher, these machines can produce good quality clichés.
Machines for etching magnesium cliches from American and English manufacturers are rarely found in Russian printing houses.
In terms of price range, these etching machines are close to the German Stoma machines.
The main advantage of blade etching machines is the ease of operation and ease of cleaning and repair.
The main disadvantage of blade machines is the large volume of etching solution that must be poured into the bath.
In the bath of a nozzle-type etching machine, under the plate being processed, there is a metal plane with nozzles built into it (or a set of nozzles located in the same plane). A tank with a working solution is located under the etching bath.
In this tank, the required temperature of the solution is maintained using the same elements that are used in the shoveling machine (heating element + coil + temperature sensor).
The working solution is pumped from the tank using a compressor and, through a system of nozzles, is thrown onto the plate.
Next, the solution collects at the bottom of the bath (under the nozzle system) and flows back into the tank. So it circulates in a circle.
Nozzle-type etching machines include some American-made machines and old Odessa-made zinc printing machines, used in the USSR for the production of letterpress cliches.
Recently, nozzle-type etching machines have hardly been used for etching magnesium.
This fact is associated with the more complex design of nozzle systems in comparison with blade machines, and, accordingly, with greater difficulties in preventive and other repair work.
But in some Russian printing houses they reconfigured old Odessa zinc-etching machines to work with magnesium plates and, with the high professionalism of the etchers, they obtain magnesium cliches of excellent quality.

The main advantage of nozzle machines is the more economical use of the solution: we can not fill the entire tank. The main disadvantage of nozzle machines is the difficulty of cleaning them if they become clogged: it is difficult to find which nozzle is clogged, and it is difficult to clean the solution supply pipes to the nozzles. According to Western experts, blade machines produce better line cliches and dies, while nozzle machines produce raster cliches.
Because Raster cliches are rarely made on magnesium (this is more the prerogative of copper cliches), and the use of nozzle machines for etching magnesium is not advisable.
But for etching copper raster cliches, nozzle machines are quite suitable.

Technology of etching magnesium (and zinc) cliches.

Magnesium etching is carried out in a 20% solution nitric acid with the addition of a surfactant.
During the etching process, the pressure of the working solution is created in the etching bath on the magnesium plate.
As a result of this pressure, magnesium is etched from the plate with the formation of magnesium salt, water, some gases and a large amount of heat.
Due to the presence of a surfactant additive, it is possible to obtain a positive etching angle (without etching).
By adjusting the temperature of the working solution and the speed of throwing the solution onto the plate (rotation speed of the blades), we can change the etching angle according to our wishes, depending on the embossing method, embossing depth and embossed material.

Before etching begins, the machine is in the mode of mixing the working solution, since the solution is in an emulsion state.
The emulsion must be stirred all the time so that it does not separate into separate layers.
If the process of mixing the solution is stopped, the surfactant additive floats to the surface of the solution, forming a kind of film.
It is in connection with this property of the solution and the characteristics of those. process, etching magnesium (and other) plates with a positive etching angle without special equipment (throwing a well-mixed solution onto the plate) is impossible!

Technological process etching magnesium clichés:

1. Prepress: computer design and, as a result, film output on a photo output machine (negative or positive film - depends on the type of photoresist on the magnesium plate).
When making a photo print, it is necessary to take into account the coefficient of thermal expansion of magnesium, equal to 0.0029% per 1 degree Celsius (for example, at an embossing temperature of 120 0C and at a room temperature of 20 0C, the size of the original layout is 0.9971 of the actual size of the cliche).
2. Cutting out a blank for the future cliche with dimensions larger than the cliche format by 5 mm on each side (technical fields for cutting, processing the edges of the cliche and etching).
Retouching the edges of the plate to protect them from side etching.
3. Illumination of the photoresist through the original film in the UV copy frame.
4. Developing (washing) the unexposed photoresist of the plate.
5. Checking the development result and retouching the image with retouching varnish if necessary.
6. Preliminary etching of the plate (fixing the photoresist and preparing the surface of the plate for etching).
7. Etching the plate through a stencil of exposed photoresist.
8. Mechanical modification of the plates: removal of excess points and processing of the side edges of the plate (chamfering, if necessary).
9. Chemical removal of photoresist residues from convex cliche elements.

The cliché is ready!

The technology for etching magnesium cliches described above is common to all types of etching machines, however, each supplier of equipment and consumables for etching cliches introduces some additions to this technology.
Typically, these additions come down to the invention of several chemical solutions for working with wafers (developer, surfactant additives, photoresist removers, etc.), and also change the proportions of the etching solution.

Etching copper plates

The technology for etching copper plates is more complex than the technology for etching magnesium, although it is similar to it.
When etching magnesium, we can completely predict the resulting cliche: by adjusting the speed of rotation of the blades, the temperature of the solution and other parameters, we can obtain the predicted etching angle, etching depth and other parameters of the cliche.
When etching copper, everything is much more complicated, because... the solution for etching copper is much more complex - instead of one surfactant additive used in etching magnesium, there are three or even more additives in the solution for etching copper.

There are only six additives in the etching solution for copper (300 Be ferric chloride solution), and their combination depends on the type of copper cliche that we want to obtain: a deep spot cliche or a shallow raster cliche.
An antifoaming agent is a permanent addition to the etching solution.
It floats on the surface in the form of a thin film and prevents the formation of foam.
All additives for copper etching are divided into renewable (requiring renewal after each plate etched in a solution and after a long break in etching) and non-renewable (added to the solution once and no longer added until the solution is replaced).
In comparison to the magnesium etching process, the surfactant additive, the only additive for magnesium etching, is non-renewable.
In the etching solution, renewable and non-renewable additives combine to form a complex organic surfactant mixture, which is absorbed onto the surface of the copper plate during the etching process, guiding the etching process to obtain a positive etching angle.
Over time, renewable additives lose their working properties, the surfactant mixture stops working correctly, and the addition of renewable additives is required.
So, for example, if the car stood idle overnight, then in the morning we will need to add a full portion of the renewable additive to the etching solution, because Yesterday's supplement no longer works.

Equipment for the production of copper clichés

Equipment for etching copper plates is similar to equipment for etching magnesium cliches.
The main difference is in the materials: copper machines are made of plastics (acid-resistant PVC), while the blades and metal parts are made of titanium.
There are manufacturers of copper production machines in the USA and England, Germany and Japan.
In Russian printing houses they work on German and American machines.
If in the pickling of magnesium blade machines are used in most cases, then in the etching of copper blade and nozzle machines are used equally often.
Both types of machines produce copper cliches of the highest quality.
When etching copper, the quality of etching depends more on the professionalism of the etcher than on the design features of the machine.
When etching magnesium, the quality of the finished cliches is less related to professional qualities pickler, because everything can be taught quickly, but when etching copper you need experience and more experience.

Copper plate etching technology

Let's move on to the technology of etching copper plates.
The operations for illumination, development and pre-etching are similar to the procedures for etching magnesium (see above the technology of etching magnesium plates), the only difference is in the composition of the solutions and the coefficient of thermal expansion of copper (taken into account when removing films): it is two times less than for magnesium.
After the preliminary operations of processing the copper plate, we move on to the etching process.
Due to the great complexity of the technology, copper etching is carried out at a constant temperature and a constant speed of rotation of the blades. Thus, we get rid of unnecessary unknowns in the formula for obtaining high-quality copper clichés.
We adjust the cliche etching angle by changing the amount of surfactant additives (and testing after each etched plate to see if they need to be added), and the etching depth by changing the etching time.
Additives are diluted in a ratio of 1:10 with a clean etching solution (300 Be ferric chloride solution).

The etching solution is prepared as follows:
1. Pour the required amount of ferric chloride solution with a density of 300 Be into the etching bath.
2. Add a small amount of antifoam.
3. Add solutions of the necessary non-renewable and renewable surfactant additives.
4. Test the solution (using special test clichés).
5. Add a solution of a renewable surfactant additive and test again, adding the solution until we get a test that satisfies us.

When adding a solution of a renewable additive, if there is an excess amount of it in the etching solution, it is enough to stir the solution for several minutes in operating mode.
Thus, part of the additive loses its working properties. After this procedure, the etching solution is tested again. When we finally get a good test, we put the build plate in the etching machine and etch it to the required depth. As mentioned above, copper plates are not etched to a depth of more than 1 mm.
This fact is due to the fact that the solution for etching copper and surfactant additives are quite expensive, and the more copper we etch from the plate, the faster the solution becomes saturated with copper salts and loses its performance. To save money, etching is carried out to a depth of 1 mm, and the cliches are milled to a greater depth.
Another reason for shallow etching of copper is the dependence of the minimum line thickness on the etching depth: with a large etching depth, the likelihood of thin lines being etched increases.
After etching, the cliches are washed and the remaining photoresist is removed. Next, mechanical modification of the cliche is carried out.
Mechanical modification includes milling space elements to the required depth, removing excess points and milling chamfers on the edges of the cliche (if necessary).
After mechanical modification, the cliche is ready.

Before the next etching, a renewable additive is again added to the etching solution and test cliches are made.
When a certain concentration of copper in the etching solution is reached, the solution is drained, the etching bath is washed and a new solution is made.
The concentration of copper in the solution is checked using a spectrophatometer (the most accurate method), or by measuring the weight of copper dissolved in the etching solution (we add together the differences between the weight of the plates before and after etching).

Etching brass cliches.

As mentioned earlier, little is done in brass etching and it is done only to a small depth (0.2 mm - 0.3 mm).
This is due to the fact that brass is a copper-grade alloy.
If we examine brass at high magnification, we get a structure of copper particles filled around with zinc.
When pickling, zinc is etched much faster than copper.
As a result, the etched surface of the brass is rough and fragile; the side edges of the printed elements also have the same properties.
When etching, we also cannot obtain straight boundaries of printed elements, since all printed elements have a border of notches. To this day, surfactant additives have not been created to obtain a positive angle of inclination of the edges of printed elements during the etching process, which is also not acceptable for cliches.
All these facts lead to the fact that clichés for hot stamping are not made by etching brass; it is easier to process brass clichés mechanically (by engraving).

Etching of steel clichés.

Pickling steel is a rather complicated process, since there are no surfactant additives to obtain a positive etching angle.
But, unlike brass, steel is difficult to machine.
To save time and tools when engraving steel cliches, the plates are initially etched to the required depth (with a negative etching angle), and then modified on an engraving and milling machine to obtain a positive angle and precise cliche shapes.
Steel is pickled in the following solution: hydrochloric acid + sulfuric acid + silver chloride (AgCl2).
In the same way, die-cutting knives are made on a solid steel sheet (for rotary die-cutting).

Mechanical method of making metal cliches (cliché engraving).

As mentioned above, the chemical method of making cliches for hot stamping is the most popular.
But, unfortunately, such a fast and fairly simple method for the production of embossed (three-dimensional) matrices and cliches is not suitable. In this case, we use a mechanical method of processing metal plates - engraving.
Engraving can be manual or automatic.
Manual engraving of metal plates is one of the oldest methods for making clichés and forms for letterpress and intaglio printing, hot stamping, embossing and blind stamping.
The manual engraving method consists in the fact that the engraver, using various hand tools (scrapers, needle files, sandpapers and pastes), cuts out a cliche from a metal plate.
This method was used, and sometimes is still used, to make absolutely any cliches and stamps.
He demands high class engraver and a lot of time.
The role of this method decreased significantly after the invention chemical method production of clichés, as well as automatic engraving and milling machines. The manual method also includes making cliches on an engraving and milling machine with manual tool feed.

Automatic metal plate engraving is a plate processing method using CNC and PC machines. The use of engraving and milling technology under PC and CNC control is widespread and is the most popular method for producing complex 3D cliches for embossing.
When using a PC to control engraving and milling machines, the complexity of our cliche depends more on the operator’s knowledge computer technology than from experience in manual metalworking, which makes it easier to find personnel to work on this equipment.
Processing the original layout of the future cliché on a computer gives us the opportunity to visually create and correct a 3D computer model of the cliché.
The machine software is compatible with standard programs for working with 3D graphics, which allows you to use all of these powerful software products in the production of original cliche layouts.
The capabilities of PC-controlled engraving and milling machines described above make it possible to increase the quality and speed of cliche production, and also reduce the influence of the human factor on the quality of the resulting cliche (in the case of high-quality production of the original on a computer).

Computer controlled engraving and milling machines.

Modern engraving and milling machines are high-precision computerized equipment.
To move the spindle with the cutting tool, microstepping motors (the cheapest models) or servo motors with feedback are used that monitor the actual position of the spindle (the most accurate expensive models).
The spindle is driven by ball screw pairs, which ensures that there is no backlash in the system.
Cheap machines use steel cables instead of ball screws, but such systems do not have high tool positioning accuracy.
There are many manufacturers of engraving and milling equipment.
Most of them are suitable for making clichés for hot stamping and embossing.
So, for example, even the cheapest machine from Roland (Japan), model MDX-15 (its price is $3 thousand), allows you to produce simple brass dies for embossing in a 10*15 cm format.

When choosing equipment for engraving cliches, it is necessary to take into account the formats of future cliches, the cliche material and the required speed of cliche production (the required spindle power depends on the material and the required speed).
To produce a rotary cliche (for rotary embossing sections in flexographic machines or rotary die-cutting shafts), the presence of a fourth coordinate in the machine is required.
In addition to the machine itself, it is also very important software, under the control of which its work takes place.
In most cases, software for designing and manufacturing simple models (and cliches) is supplied with the machine.
To design more complex engraving objects (including complex embossed 3D matrices), standard 3D graphics software packages are used: 3D Studio, AutoCAD and others.
Next, from these programs, 3D models are transferred to programs for working with an engraving and milling machine.
In addition to special programs included with a specific machine, there are also software products that allow you to work with various engraving and milling machines from different manufacturers, for example the ArtCAM software product.
Such programs make it easier to design 3D models of cliches and speed up the engraving process by optimizing the path of movement of the cutting tool.

Materials for making cliches by engraving.

The most common material for making cliches using the engraving method is brass.
Of the Russian materials, brass LS-59 is best suited. This brand of brass is alloyed with lead (approximately 1.4%).
Lead is a kind of lubricant that reduces tool wear when cutting brass.
Small, easily separated chips formed during the machining of this brass make it possible to obtain the surface of the processed products with low roughness parameters.
Magnesium is also well processed by engraving due to its softness and brittleness.