Transfer printing is a method of moving a premade image from one location to another. This process was originally used to move images from metal or ceramic plates to pottery, while newer forms use specialty paper and will transfer to nearly anything. The basic process has ink applied to a specialty surface; that surface is pressed against the printable object, which transfers the ink. Heat is then applied to the newly inked area and the image becomes permanent. This process is similar to screen printing.
Early forms of transfer printing were used to create the appearance of hand-painted pottery while taking less work. The problem with this is the shape of the pottery’s surface. The curves on a specific piece were difficult to work with, but making a system that would accommodate any shape was even more difficult.
In the mid-1700s, a process using metal or ceramic plates became popular in England. First, a piece of pottery was created and fired to make it hard. Next, a premade plate, or roller, containing a decorative image would have ink applied to its surface. The plate was then pressed or rolled over the surface of the pottery, transferring the ink. After the ink was transferred, the pottery was glazed and fired again to make the ink hold fast to the pottery’s surface.
For the most part, transfer printing didn’t change for a very long time. The processes and techniques evolved very little until the later part of the 20th century. Until then, transfer printing was less expensive than hand painting objects, but not by much. The specialized equipment, premade plates and additional manufacturing steps ate far into any additional profits.
Modern operations have a much more cost-effective method of transferring images. Industrial printers can put the ink onto specialty paper which is then pressed against the object. The object is then flash heated, permanently transferring the ink. The speed and localization of this process allows it to work on a wide range of materials, including those that would be damaged by the unfocused heat used in the earlier forms of transfer printing.
A similar process, called screen printing, is used to transfer images to paper or cloth. In this process, a fine screen is first covered in ink in. Then the inky screen is pressed against a surface, transferring the ink over to the work object. The newly inked object is generally allowed to air dry. Although sometimes low heat is applied to the object to speed drying, it is much less than what is used in transfer printing. While the basics of the process are the same as transfer printing, the two technologies are usually kept separate since screen printing does not require additional heat.