Hot Foil printing as we know it, has gradually evolved over hundreds of years, but the background concept and use, goes back thousands of years. Over 4000 years ago, in ancient Egypt, craftsmen beat gold with a hammer until a thinness of an amazing 0.1 microns (0.0001mm / 0.00000394”) was achieved. This gold leaf was then used to embellish buildings, mummies, jewellery, decoration of arms, coffins and much more.
In the Middle Ages, mechanical machines were developed that were used for printing. Monks started using these machines with gold leaf to print onto book covers for easily identification. They used various materials to create the impression tools required, which included steel type and engraving / carvings. The Monks embossed the impression onto the leather cover, and then rubbed the gold leaf into the embossing, by hand. This early form of foil printing was widespread until the early 19th century. In order to simplify the application of gold leaf onto an embossed impression, gold leaf was bonded on to paper. Heat and a small amount of pressure was used to separate the gold from the paper and transfer to the embossed leather. The heat helped remove the gold from the paper and also helped the gold leaf stick better onto the leather. As gold leaf was very expensive to use, wide spread use was not possible. In the early 20th century, a series of relatively low cost metallic foils started appearing in the market to replace the very expensive gold leaf foils. These low cost foils helped advance the use of foils in printing. Today, hot foil printing is used to prints onto a large range of products, and is increasing in popularity as a method of printing.
Hot Foil printing is a printing technology where heat, pressure, a printing die (or type) and a thin metallic film (foil) is used to imprint metallic images (text and graphics) on to various materials. Hot foil printing produces an incredible looking impression on the printed surface and is increasingly becoming the preferred method of printing. Hot Foil printing is also referred to as hot stamping, foil printing, dry stamping, flat stamping, gold stamping, blocking, and leaf stamping. There are various types of foil printing techniques that can be used depending on your design needs. Foil printing is also referred to as dry printing, because it does not use ink when printing. Heated metal type, metal printing plate (die), silicone die or a hot foil polymer plate is heated to the required temperature. When the heated image comes in contact with the foil, a thin layer of coating of the impression on the print die, transfers onto the intended substrate. In other words, the heated die presses against the foil, the heat and pressure releases the colour layer from the foil roll and bonds it onto the end product or substrate. Foil printing produced flat print impressions only but if combined with embossing, a 2½D, 3D impression is possible. This mix is known in the industry as foil embossing or combination work. Hot foil printing is the only printing technology capable of applying bright, non-tarnishable metallic effects to paper, cardboard, plastic, wood, fabric and other surfaces.
Printing foils are available in a wide range of colours, finishes and effects, from marble,
Imitation leather, pearls, wood grains, and designs to holograms, pigments, Metallic’s, and subtle tints, in matte and gloss finishes. Foils can be economical made to order, if your requirements are large enough to justify the minimum manufacturing quantity required. Foils can be made to Pantone® colours, custom colours, multi-colour, with designs, effects and or finishes.
For best results we recommend that you discuss the order in detail with your supplier(s) before you source the materials and or start printing. Substrate, die, foil type and colour selection are all key elements in the success of an embossed and or foil printed product.
Types of Hot Foil Printing
There are a number of ways you can hot foil print. The different hot foil technologies available are not very dissimilar in terms of technology, but mainly differ from each other in the type and appearance of the finished product, that are printed on them. The type of foil used when hot foil printing also determines the look and finish of the printed product.
When we talk about foil transfer it is referring to the actual foil coating and not the thin polyester carrier.
A brief look at the different foil stamping technologies:
Flat Foil Printing
Flat foil printing is the most common and so the most popular form of foil printing in use today. It is a comparatively simple and cost effective technology against alternative foil printing technologies. In flat stamping, the foil is transferred onto the substrate using a flat die stamp that is made of magnesium, copper or (hot foil) photopolymer. The finished result is a foil print that is a few microns thick on the surface. Depending on the pressure setup you can achieve a flat level print or a flat indented print on the substrate or product you are printing onto. If you wish to achieve a raised (embossed) look using flat foil printing on your substrate, you firstly need to foil print the image, then emboss the same image with a female etched or engraved die and a male counterforce, giving you your 2½ or 3D image.
Multi-Level Foil Printing (AKA Sculpted Foil Printing)
Multi-level hot foil printing is achieved with a printing die that has more than one level. Multi-level foil printing produces a printed image that is hot foiled and embossed at the same time. The various levels and elements of the design are brought out superbly and distinctly. Multi-level dies are generally made from brass and are typically CNC engraved or hand carved. In some cases CNC engraved dies are then hand carver to further enhance the design. This method of foil printing produces superb finished results but is far more expensive than regular flat foil printing.
Vertical Foil Printing
Vertical foil printing technology is used for printing onto flat or slightly doomed products, parts and substrates. This print technology is also used to print parts and or products that are cylindrical in shape, but only to a maximum of 90 degrees of the outer perimeter of such parts.
Peripheral Foil Printing
Peripheral foil printing is the technique used to apply foil heat transfers onto the outer perimeter of various parts, products and or substrates. With peripheral foil printing, unlike vertical foil printing, you can foil print onto the entire 360 degrees of the circumference of the intended part and or product.
Toner Foil Printing (AKA Sublimation printing)
Toner foil printing is a fairly new technology in comparison to Flat, Multi-Level, Vertical and Peripheral Foil Printing. All the other technologies rely on some form of die made of metal, polymer, silicone or even metal type to transfer the image onto the substrate. The toner foil bonds onto pre-printed images produced on a laser printer or photocopier. This naturally somewhat limits you to what you can print onto. Glossy papers and cards including laser printable plastics such as overhead projection film and so forth are strongly recommended as the printed media of choice, for this technology. Toner foil printing as the name suggests is where a special kind of foil bonds under heat and pressure to the laser or photocopier toner pre-printed on the substrate. A good quality heat (and speed) controllable laminator, a toner foiling machine and or a standard flat plate hot foiler with a silicone plate attracted to it, can all be used.
Cold Die-less Foil Printing
This foil technology is new and up and coming. The basic core technology is that an adhesive is printed on the substrate using Offset Litho, Flexo or even Letterpress printing. A special type of foil is then feed over the image and pressed together under pressure. The foil coating bonds to the adhesive image area and then separated from the printed substrate. The adhesive image area will now have foil bonded to it, and depending on the type for foil used; you are able to overprint spot or full colour on the foiled area producing amazing results. The final colour of the image now comes from the colours of the printing ink.
Depending on the type of finished you wish to achieve, and the part, product and or substrate you wish to print onto, determines the foil print technology you need to use.
The cornerstone of modern hot foil printing is the printing foil. The very essence of foil printing is the printing foil that is pressed with metal type or a die onto different materials, products and or parts, along with heat and pressure, to make vibrant imprint.
Types of Foil
There are a range of printing foils available for use in hot foil printing. Foils are available in plain single colours, multi-colour to patterns of all sorts.
- Metallic Foils: Metallic foils have a metallic mirror like gloss finish and gives a gleaming look to the foil printed image. The foils are available in a large range of different metal shades such as gold, silver, bronze, and copper with a variation of shades within each colour. In addition, metallic foils are also available in other colours such as white, green, blue, black, brown, red, orange, yellow, pink, purple and much more, again with a variation of shades within each colour.
- Gloss Pigment Foils: This type of foil does not have a metallic look but has a very high lustrous finish. Using this type of foil gives a glossy look to the imprint. Gloss foils are available in a large range of different colours and shade variations.
- Matte Pigment Foils: The range of colours available, are the same as the gloss pigment range, but in a dull finish, hence the name matte foil. The solid white pigment colour foil is classified as a matte foil and so is available in this range.
- Holographic Foils: A multi-dimensional image foil made photographically with the use of lasers and special optics to produce a hologram. Such hologram images are transferred on unique foils, which are then known as holographic printing foil. These kinds of foils give a very special, motion effect to the foil designs.
Most foils for stamping are comprised of five layers:
- A thin Polyester Film Carrier is used to protect the foil layers and to permit rolling.
- The Release Coat allows the other layers to release from the film carrier upon application of heat and or pressure.
- The Lacquer or Colour Coat carries the colour tint in the form of dyes or pigments. Most often this layer is transparent or translucent, which allows the introduction of the metallic layer in metal foils.
- The Metal Coat is generally composed of aluminium to provide the reflective qualities and opacity desired in metallic foils.
- The Adhesive Coat serves to bond the foil to the substrate being stamped. The
printability characteristics of foils are primarily determined in this coat by employing more or less adhesive.
The selection of foil for printing depends on many factors such as:
- Different foils have different characteristics in terms of durability, scratch resistance, fade resistance, chemical resistance, brittleness, opacity, adherence, along with colour and surface characteristics.
- Every manufacturer’s colours are different unless made to an international colour reference like Pantone®. Even foils that appear the same can have completely different characteristics that are not immediately recognizable, as they are intended for different applications.
- Foil printing can be used for many different applications and can be printed on various materials including paper/ card, plastic, leather, fabric, felt, vinyl, rubber and wood. Foil selection is very dependent on the substrate you will be printing onto.
- When printing onto paper or card, choosing the right foil is very important. You will need to use a foil that is resistant to high temperatures if the substrate is going to feed through a laser printer and or photocopier.
- Foil may not be compatible with each other. If you are using two different kinds of foil, which overlap one another, then you need to choose a foil that will stick to each other.
- The colour of the substrate or product you wish to print on will limit your selection of foil colours. The range of colours available for printing foils are limited, especially for obscure foil grades, so that may determine your foil / substrate selection.
- As in most artistic medium, these characteristics should be accepted as an opportunity for innovation. The selected foil and substrate characteristics, and the depth and complexity of the artwork and dies, are all variables, which will control the final result.
- Foil printing is an incredibly flexible process that allows you to discover imaging on any number of surfaces to which conventional printing techniques cannot be applied.
- Your local raw material suppliers are best placed to help and guide you through the selection process.
With the large range of products available from various manufacturers and suppliers, why not let your creativity to go wild. By experimenting and using the different types and shades of foils, you can achieve amazing results.
Compliment Slips, Envelopes, Leather Key Fobs, Coasters, Bookmarks, Box lids, Favours, Ballpoint Pens, Pencils, Dart Flights, Luggage Labels, Notepads, Wedding stationery, Greetings cards, Christmas cards, Tax disc Holders, Book covers, Leaflets, Ribbons, Playing cards, Serviettes/Napkins, Plastic component parts, Diaries, and list can go on.