液態金屬
Solid ink, Hot-Melt or Phase change ink was introduced in 1962 at Teletype Corporation in the Project 176. Solid ink is the name for ink that is solid at room temperature. Wax was formally introduced in the first Solid ink product introduced with Continuous Inkjets in the Teletype Inktronic Terminal in 1966 but the patent for Hot-melt wax did not issue until Patent US3653932 April 4, 1972. In 1971, a patent, US3596285 was issued for a Liquid Metal Recorder, a printer process that fabricated metal models of symbols, patterns and characters. Liquid metal was referred to as Hot-Melt "type" ink in this patent and it was introduced before the term 3D printing was ever conceived. These are examples of three-dimensional inks (3D Inks) or inks that stand off the page.