A: Thermofoil, also known as RTF for “rigid thermofoil,” is a thin layer of vinyl that is often bonded by heat and pressure to cabinet components made from MDF, or medium density fibreboard, a type of particle board. The heat softens the plastic layer when applied and the vacuum pressing helps it conform to the shapes. This allows manufacturers to computer control a router to cut MDF, so it looks like a frame-and-panel door with a contoured center panel – even one with the vertical grooves that make doors like yours look like they are. bead panel. Topped by the vinyl layer, MDF is protected from moisture, which will cause it to swell and warp. The surface is transparent and easy to clean. And, probably the main reason why thermofoil doors are so popular: Doors are much cheaper than solid wood ones, and they don’t have to be flat slabs, as they would be if they were paneled. of particles covered with standard laminate.