toneresist
toneresist is a term that can refer to several different concepts within the realm of electronics and materials science. In the context of printed circuit boards (PCBs), a toner resist is a layer of material applied to the copper surface of a PCB to prevent etching in unwanted areas during the manufacturing process. Laser printers or photocopiers are often used to print a toner-based design onto a special paper or film, which is then transferred to the copper clad PCB. The toner, being insoluble in the etching solution, acts as a protective mask. After etching, the toner is removed, leaving the desired copper traces.
Beyond PCB fabrication, "toneresist" could also be a colloquial term for a material or coating designed to