How does one make thermal paper? Thanks! Any information would be appreciated.?

Answer 1

The paper is impregnated with a solid-state mixture of a dye and a suitable matrix; a combination of a fluoran leuco dye and an octadecylphosphonic acid is an example. When the matrix is heated above its melting point, the dye reacts with the acid, shifts to its colored form, and the changed form is then conserved in metastable state when the matrix solidifies back quickly enough.
(from Wikipedia).
Another method is using a paper with a coating of aluminium, and a "sparkling" print head. Each sparkle burns the paper, leaving a black "pixel".