Heat-transfer printing, also referred to as thermal printing, thermal-transfer printing and thermal-wax transfer, uses heat to transfer an image from wax to an object. Thermal-based printing methods work with pre-printed images on a single wax sheet or produce printed-on-the-fly images made by layering wax dye onto an object. Heat-transfer printing can replace or supplement alternative printing methods.
Materials for Printing
A heat-transfer printer requires a type of wax-based ink ribbon to create an image. The printer works by pressing the ribbon against the printing object and heating the opposite side until the ink melts off the ribbon and transfers to the object. The wax-based ink ribbon can work two ways depending on the printing process. The desired printing image may be inked onto the wax ribbon and applied as is through heat and direct pressure. Alternatively, the printer may use four ribbons -- in cyan, yellow, magenta and black -- to draw the image during the printing process by layering colors on the printing surface.
Fabric and Novelty Materials
Like its inkjet counterpart, heat-transfer printing works well on paper, but it excels in applying images to a range of materials that include garments and textiles. For example, a heat-press T-shirt maker transfers an image onto a piece of fabric. Heat-transfer printed images are durable, heat resistant, adhesive and water resistant. Heat-transfer printing can be used to print on physically hard objects and acrylics like coffee mugs.
When Heat-Transfer Printing Is Ideal
Heat-transfer printing is more useful for some printing situations than others. When applied correctly, heat-transfer printing produces high-quality, colorful prints of photo-realistic images, which makes it useful for digital photography prints. Heat-transfer printing works well for adding or customizing prints on fabrics such as athletic uniform numbers. Because heat-transfer prints are durable, they work well when the printed object is exposed to the elements. Heat-transfer printing is a better long-term solution than using direct-thermal printing, which is known to wear out.
Direct-thermal printing is a type of heat-based printing that burns an image into an object on heat-sensitive materials. Direct-thermal printers do not need any sort of ink or wax to create images; instead, they use coated paper that changes from white to black when heated. Direct-thermal and thermal-transfer printing are both commonly used for creating labels and receipts. Heat-transfer printing is recommended over direct-thermal printing for labels and paper that need to last more than half a year, but direct-thermal printing is cheaper and requires stocking only one material for prints.