PBT

PBT, short for polybutylene terephthalate, is a plastic commonly used for keycaps because it holds up well against years of finger oil and friction. Keycaps made from PBT tend to keep their original texture and matte finish much longer than cheaper alternatives, resisting the shiny, slippery patches that develop on frequently pressed keys.

Compared to ABS, PBT is generally thicker and has a slightly grainier or sandier feel, though the exact texture depends on the manufacturing process and mold. PBT can also be more prone to warping during manufacturing if not produced carefully, which is why quality varies between keycap sets even when both are labeled PBT.

When shopping for PBT keycaps, check whether the legends are dye-sublimated or doubleshot, since PBT can be harder to doubleshot cleanly than ABS. A common point of confusion is assuming all PBT keycaps sound and feel identical, when wall thickness, keycap profile, and manufacturing quality all affect the final feel as much as the base material does.