Both styles of keycaps come in PBT, but you have your choice between gray top-printed dye-sub, and white laser-engraved front-printed keycaps. Laser-engraved legends are burned right into the keycap and the deep grooves are covered with infill to retain a smooth feel. For long-lasting construction with no surface imbalance, dye-sublimated legends infuse the plastic with dye, the most durable possible construction that also retains a smooth hand feel.