In spite of the fact that it sounds like a bit of a contradiction in terms, solid ink printing is in fact a technology used in some computer printers. These printers use solid ink sticks or balls instead of the fluid ink or toner powder. The solid ink is melted before use, so it does indeed become liquid at some point. It “freezes” back to solid state almost immediately it contacts the colder paper, and this quick dry capability is one of the advantages of the system. On the other hand the need to melt the solid ink means that it takes about a quarter of an hour to “turn on” the machine — it’s better to leave it on thereafter.

Xerox has claimed that solid ink printing produces more vibrant colors than other methods, and this results from its quick dry action, giving it less opportunity to be absorbed into the paper surface. They have also claimed as advantages that solid ink printers are easier to use, can print on a wide range of media, and are more environmentally friendly. Solid ink printing was originally developed by Tektronix, who introduced the first solid ink color printer in 1991. In 1995 they introduced a modification allowing the machine to utilize an offset drum, which overcame the huge problem of a heavy print head jerking back and forth, which tended to make the whole machine walk across the floor!

Yellow, cyan, magenta, and black solid ink sticks made by Xerox

 

 

 

 

 

 

Xerox acquired Tektronix’s printing division in 2000. Whatever the advantages of solid ink printing, Xerox does not sell solid ink printers any more.

There’s a thorough article at Imaging.org which explains the operation of the machines in some detail.