SP offer pad printing, but not silkscreen (and are not aware of the existence of the latter). EK believe that silkscreen is manual labour only, with no UV protection option. Devlin would be surprised if anyone used silkscreen. Cherry ridiculed the claims of silkscreen printing.
I'm going by products sold in the UK — it's virtually all "decal" style. That's virtually all I see, from any consumer or business brand, year upon year. It's some sort of hardened coating (which isn't, as it comes off easily, and the writing along with it) over flat painted legends.
Filco keyboards are claimed to be pad-printed too, but I've never seen any official word on their printing technique. The all-over spray coating though is evident from examination of a keycap (you can see all the spray splatter on the underside). Most high-end brands now prefer laser, and recently laser has reached the point that vivid white on black is possible. The only company who ever pulled off the scorched gold-on-black look is Topre, where it looks more like gold thick ink printing.
Depending who you ask, you get a completely different story, and nothing anyone says accounts for reality. Part of the problem is that all the companies accessible to English speakers, are high-end and specialist companies!
