Heat press transfer comes in numerous paper types to suit the imprint method used, and the product the imprint is transferred to. Traditional heat transfers are screen printed, but modern transfers can be printed by inkjets and laser printers using special papers. The basic function of all heat transfer papers is to "transfer" the printed image onto an item by use of heat and pressure.
Hot-split Screen Printed Transfer Papers
Hot-split transfer papers for screen printing are coated with silicone, and are removed immediately after heat and pressure application. Hot-split transfers leave a small amount of ink on the paper after peeling, producing a softer feel to the imprint because the ink film has been "split".
Cold-peel Screen Printed Transfer Papers
Cold-peel transfer paper for screen printing is a parchment paper. It is allowed to cool slightly after application, and produces a brighter imprint due to complete ink film transfer. Screen printed cold-peel transfers feel more like direct screen printing, with a slight rubbery feel to the image.
Inkjet Printed Transfer Papers
Inkjet transfer papers are printed with special inkjet "sublimation" inks. Sublimation transfers the ink from the paper to the item when ink is heated into a gaseous state. Sublimation transfers produce a very soft imprint feel on fabric, but are also used to imprint specially-coated hard goods such as mugs, and other decorative, promotional, and utility items. Both warm and cold-peel sublimation methods can be used depending on the item being imprinted. Sublimation transfers can only be applied to polyester-coated surfaces, or garments with a high polyester content. Since the ink is transferred as a gas, the imprint penetrates the polyester much like a dye, and is quite permanent.
Laser Printed Transfer Papers
Laser printed transfers can also be printed with standard inkjet printers, and contain a special protective coating that is transferred along with the imprint. This type of transfer is used mainly for cloth goods, and produces a bright imprint with a transparent, filmy coating.
Specialty Transfer Papers
Some transfer papers offer special finishes, such as glitter, to further embellish items. The glitter is coated on the paper surface, and is transferred to the item during the imprinting process. Special "puff" ink papers for screen printed transfers allow ink with puff additive to be transferred to garments with the desired effect.
Ink Film Transfer Papers
Ink film transfers are pre-coated with plasticized ink, from which the design is cut by hand or with a vinyl plotter connected to a computer with graphic arts software. The film surrounding the cut lettering or design is removed (weeded), and the remaining ink film is heat transferred onto a garment. This transfer type simulates direct screen printing, with a durable, rubbery feel.
Transfer Paper Tips
Transfer paper, like any paper, should be kept in humidity-controlled environments when not in use. Humid or very dry conditions can cause paper to swell or shrink, affecting print quality and application performance. Purchase transfer paper that suits your particular or preferred printing method, and test all papers for suitability before using for customer jobs.