Ultimate Linings are a 100% solid polyurethane spray coating formed by mixing a specially-formulated chemical with a catalyst. The absence of solvents allows the material to solidify within a half a minute, eliminating sagging and running. According to the company, permanent spray-in linings for pickups, vans and delivery trucks are maintenance free and easily repaired. Unlike drop-ins, they never crack, are a perfect fit every time, and come in a variety of colors.