gold stamping foil, silver foil
Hot stamping is a dry printing method in which a heated die and foil are used to apply graphics to a surface. This is one method of security printing.
Hot stamping is a straightforward process:
- A die is mounted and heated,
- Foil is positioned above the material to be imprinted,
- A combination of heat, dwell time, pressure and stripping time control the quality of the stamp.
Foil stamping is environmentally friendly due to it being a dry process. It does not use solvents or inks and does not create any harmful vapors.
A successful hot stamping job is directly related to the quality of the original artwork. In order to insure the highest quality reproduction of an imprint, the original artwork should be “camera-ready”. The better the artwork at the beginning, the better the imprint reproduction result. The key to a successful hot stamping job is threefold; the first is creating a fixture to support the part firmly under the decorating area. Second, the fixture must also position the part for repeatability of the graphic location. And third, the fixture must allow the operator to easily load and unload the part from the fixture.
An anvil is usually made of a hard rubber or phenolic.
FOIL ROLL LEAF is the ink of a hot stamping operation. It is made up of a carrier with a series of coatings to be transferred.
Substrate – a wide variety of substrates is suitable for the hot stamping process. Surface tension of the substrate has the same effect on hot stamping as it does on printing.
The hot stamping die is an engraved plate where the non-printing areas are relieved.
HEAT + PRESSURE + TIME = FOIL TRANSFER Foil is transferred to the substrate when a heated die forces the foil onto the substrate against the anvil.
A) Small and Medium sized production and substrates:- Principles are:
1. Flat Foil Stamping
2. Sculpted Foil Stamping (Multi-Level Foil Stamping)
3. Vertical Foil Stamping a maximum of 90 degrees
4. Peripheral Foil Stamping entire 360 degrees
- Machines are: 1. Hand-operated Foil Stamping Machine 2. Pneumatic Foil Stamping Machine 3. Foil Fuser Machines
B) Large sized production – Principles are:
1. Flat-Flat Principle
2. Round-On-Flat Principle
3. Round-On-Round Principle
- Machines are: Categorized to web and sheet fed stamping or embossing machine
ROTARY HOT STAMPING Short dwell time is also the reason rotary hot stamping is able to produce a greater level of detail than the best flat bed equipment. ROTARY HOT STAMP EQUIPMENT First it must maintain the desired temperature of the die. Second it must hold the die securely in position to produce even depth of impression through heavy and light coverage regions of the die. TEMPERATURE CONTROL IMPRESSION CONTROL The second task of any rotary hot stamping system is that it maintains an even depth of impression.
Die materials are divided in to metal and silicon rubber dies in which four metal materials are most often used for die construction: magnesium, copper, steel and brass. The material used for a specific application depends upon a number of factors Tooling is CNC engraving Silicon they will conform much better to parts that are not perfectly flat
Types of dies
- Single-Level straight and level
- Multilevel distinct levels of depth are used to add a variance in dimension to the image
- Round Edge provides a soft edge effect rather than a hard ruled edge.
- Beveled Edge provides the appearance of combining the softness of a round edge with the well defined lines of a distinct edge
- Sculptured a hand-tooled die
- Rotary Die Cylinders
- Copper alloys used exclusively in rotary stamping in which the time taken in one stroke which is called dwell time is extremely and very short.
- Thermally compensated for precise register and fit.
- Available for all narrow to mid web presses.
- Superior surface finish for improved accuracy.
Foil is an extremely thin polyester film material containing a dry pigment that is transferred to substrate (such as: paper) by the use of heat and pressure.
Foil composition: Film carrier: The thinner the carriers while all other things being equal, the faster the foil will transfer
Release Coat: Allows the other layers to release from the film carrier upon application of heat &/or pressure in which this layer affects whether or not a foil is suitable for fine copy or heavy coverage
Lacquer, Tie or Color Coat provides a hard abrasion resistant surface to the foil when applied and carries the color tint in the form of pigments or dyes which is required to make gold or other colored metallic because the metallic layer is always made from aluminum.
Metal Coat: Generally composed of aluminum to provide the reflective qualities and opacity desired in metallic foils.
Adhesive or Sizing Coat: The final layer in the foil construction is the sizing which serves to bond the foil to the substrate being stamped.
Types of materials
Metallic foil construction has a metal-like sheen and gives a shiny and shimmering look to the foil stamped design. Such foil paper is available in different metal shades such as gold, silver, bronze, and copper just to name a few. Pigment Foil Construction: Gloss Pigment Foil Paper not have a metallic look but has a very high glossy finish. Matte Pigment Foil Paper a dull finish as opposed to a glossy finish Holographic Foil Paper: hologram is a 3-dimensional image that can provide a distinctive appearance to specific areas of a digitally printed application.
Many other applications can be applied on the hot stamping machines without stamping or with the addition of stamping to it like:
- Debossing opposite of embossing it is indented
- Embossing by providing a three dimensional or raised effect on selected areas
- Blind Emboss provides a clean and distinctive or subtle image on paper stock does not include the use of ink or foil to highlight the embossed area.
- Registered Emboss a process that places the embossed image in alignment with another element created with ink, foil, punching, or with a second embossed image.
- Combination Emboss embossing is the process of embossing and foil stamping the same image. It involves imprinting and aligning foil over an embossed image to create a foil emboss.
- Pastelling the process of using a combination die to provide a subtle antique appearance to a substrate that is embossed and foil stamped.
- Glazing an embossed area that has a shiny or polished appearance.
- Scorching similar to glazing except that it is not used to polish the stock. Instead, scorching does what it implies: as the temperature of the die heating plate is increased beyond a normal temperature range, a scorched effect is created in the embossed image, which results in an antique or shaded appearance.
Hot stamping foil:
Foil stamping uses heat and hot stamping foil in a specialty printing process that produces a shiny design on paper, vinyl, textiles, wood, hard plastic, leather, and other materials.
Foil stamping, also called hot stamping, dry stamping, foil imprinting, or leaf stamping, can be combined with dimensional embossing to make letters and images on business cards, book covers, gift cards, office folders, and a whole host of professional or personal items.
Instead of using magnetism, plates, or inks to print words and shapes, foil stamping uses dies, or sculpted metal stamps. The heated dies seal a thin later of metallic leaf onto a surface. The foil comes in a wide roll, large enough for several passes, backed by Mylar. The hot die works similarly to a letterpress. Once heated, it presses the foil against the substrate material with enough pressure that the foil sticks only in the intended places, leaving a slight imprint.
Using several layers of foil in different colors or combining ink and foil can embellish this simple “flat” stamp. Imprinting and embossing adds even more dimensionality. The edges of the foil stamp may be straight, curved, or sculpted to make the image pop or float above the page.
Foil leaf is available in every imaginable color and pattern, like standard gold or marbleized green. Rarer types of leaf come in matte, pearlescent, holographic, opalescent, or glossy finish. Semi-transparent layers allow an under color to show through. Not only does it provide a uniquely vibrant image with depth, foil stamping can be applied to a much more diverse selection of substrates in comparison to ink.
The cover of a leather photograph album could be printed with your family’s monogram, or a cloth bookmark with a favorite literary quote. Impressive wedding invitations might have intertwining silver vines, blue flowers, and gold rings. Businesses use foil stamping to identify folders, cards, signs, and magnets with their logo. The reflective and unusual treatment is sure to catch the eye of a potential customer.
PS: It come from Wikipedia