The process of transferring a design onto another item through heat and pressure is called dye sublimation. This process can be performed on a variety of different materials, including clothing items like t-shirts and sweatshirts, mouse pads and coffee mugs. When applying designs onto mugs, you'll need a special kind of paper to produce a clean, crisp transfer and avoid ink runs or smudges.
Printing for Heat Press Transfer
Dye sublimation printing requires specialized equipment to print and then transfer the design onto the mug. Special sublimation ink must be used, in printers with large enough spray nozzles to accommodate the ink. This ink is printed on specially coated sublimation paper, which is specifically used for heat press transfers as it properly releases the ink when heated and does not allow the paper to absorb the ink during printing. Iron-on transfer paper is not the same, and will not work in a mug heat press.
Since the mugs used in heat press transfers are typical coffee-mug size, the transfer paper used to print and transfer the design must be trimmed down to fit the size and shape of the mug properly. An ordinary paper cutter will work to trim the excess paper from the design and allow the paper to fit into the mug heat press properly.
Mug Dye Sublimation
Once the design is printed and the paper trimmed to the proper size, it's time to apply the design to your mug. The mugs used in dye sublimation are a special type, and contain a special polymer coating on the outside. It's this coating that the ink bonds with, and not the actual surface of the mug itself. The ink changes from a solid to a gas due to the application of heat and pressure, and this gas permeates the polymer coating of the mug to transfer the design.
Paper Sizes and Brands
Dye sublimation or heat-press transfer paper is available in a variety of sizes, from single sheets to entire rolls meant for large production dye sub printers. Efficient positioning of the mug designs will ensure a minimum of paper waste, giving you the most worth from your supplies. Some paper brands work better than others for different types of applications, so experiment with your press, printer and paper to find the right combination for the best quality.