They use basically crayons, rectangle shaped crayons of different colors that go in the top.

I can see how you might mistake a wax printer for die sub. Tektronix has a range of printers all called Phaser's with different model numbers. IIRC the 450 is a die sub and the 350 is wax.

Dye sub printers are 3 or 4 pass systems (cym or cymk). A donor roll with page size patches of cyan, magenta, yellow and black dyes is used to transfer color to the paper. The dyes build on top of, and merge with, each other. Each pixel renders 16 million color shades. No dithering. The donor roll is single use, and easy to replace. A 600 dpi inkjet is not the equal of a 300dpi die sub printer.

The only bad thing about dye sub is the cost $5-8 bucks per 8.5x11 sheet. (I'm told that inkjets can be high cost too. Depends on saturation and fill). It really makes you cry when you find all the supplies burned off by someone printing emails.

IMHO, Die sub printers are the best for printing photos. Too expensive for most anything else.