QWERkeys UV printing
For non-white keycaps, UV printed keycaps are first treated with a white base layer, onto which the legend is printed. A UV-cured, selective image protective lacquer is then added, supposedly hence the name.
The process is proprietary and full details have not been released. The colour printing process itself is not specified; it appears to be a diffusion pattern similar to that used in inkjet and solid wax printing. The colour printing resolution appears to be in excess of 300 DPI; the white base layer also has a dithered appearance that may contribute to the visibly dotted texture of the final print.
Using the QWERkeys classic video game series group buy as an example, one observation of UV printing is that the colours can or do come out fairly dark; photographs taken with a flash tend to show the legends brighter than they appear under fluorescent indoor illumination. The legend has a high gloss surface, and is visibly embossed. The colour is produced using dithering of pigment inks, which gives solid colours a grainy appearance, but does permit multiple colours and the appearance of continuous tone, instead of the single colour typically allowed in double-shot moulding.
The following keycaps are from the QWERkeys classic video game series group buy.
QWERkeys — Legend Processes