A process used to close up crevices in buildings against water, air, dust or insects. Silicone sealants form a durable, water-tight seal, but are not typically paintable. Some silicone sealants are made to be paintable with certain types of paint such as water or oil-based paints. Other sealants are paintable. Commonly sold in cartridges which are loaded into a pistol-like caulking gun (opening at the side) or barrel gun (opening at the end) for application. During the tool-working time that varies by chemistry, the bead can be pressed into the joint so that it can bond with the materials on both sides and smoothed. The time it takes for a chemical sealant to become a rubber is known as cure time and varies by temperature and humidity.