In the context of multi-decoration design, a portion may need to be output to a printing process for inclusion on the article. This component may be referred to as ‘print’ or ‘graphics’. The most commonly used commercial printing processes are:
Screen printing
Sublimation
Direct-to-garment (DTG)
Heat-transfer printing
Direct-to-garment printing is handled like most other printing from a PC: The print image is sent to the DTG printer through the MS Windows® print manager via a print driver. The image generally has a transparent background for DTG printing. DTG printing requires heat fixing to make the garment washable.
Sublimation printing is similar to DTG printing but the process uses solid inks which give a more even gradation of color compared to the liquid inks used in DTG printing. With sublimation printing, inks are printed onto a release paper and then transferred to fabric or other surface.
Sublimation means a change from a solid to gaseous state and back to a solid without becoming liquid. Thus dye particles migrate from the paper as a gas, to bond with a polymer – fabric or other material – and become solid again. The transfer is effected using high heat (205°C) and pressure, thus guaranteeing that the image penetrates and becomes an integral part of the substrate.
Screen printing is a more complex process than DTG, requiring the creation of a screen for each ‘spot color’ making up the design. Spot or ‘direct’ colors can be identified as a special ink or Pantone or other. There may be multiple screens for each one, depending on how the design is layered.
A fourth process, which is less likely to be used in the garment industry, employs heat transfer paper. Graphics are printed and then heat-fixed to a substrate using an iron or heat-press. Printers that support heat transfer media generally provide an automatic mirror function as the image must be mirrored in order to be heat-transferred to the substrate. Heat-transfer is the preferred process for point-of-merchandising substrates or media such as mugs, pens, etc.