Joint compound
Joint compound (also known as drywall compound or mud) is a white powder of primarily gypsum dust mixed with water to form a mud the consistency of cake frosting, which is used with paper or fiber joint tape to seal joints between sheets of drywall to create a seamless base for paint on interior walls. It is often referred to simply as mud or as joint cement
Drying type
Drying type joint compounds are vinyl based and harden when they dry by evaporation.
Ready-mix lightweight joint compound
Ready-mix lightweight joint compound is a pre-made form of joint compound designed for fast application and easy maintenance. The compound is a complex combination often including water, limestone, expanded perlite, ethylene-vinyl acetate polymer, attapulgite, and other ingredients. The delicate mixture of compounds gives it a creamy texture that spreads easily onto drywall surfaces and then hardens as the moisture evaporates. Drying type compound takes a long time to dry out and is used to fill holes or gaps and shrinks as it drys possibly producing cracks in thick applications. Ready-mix joint compound is usually more forgiving than the setting type of joint compound. It can be used for as long of a period of time as needed, and does not dry up unless left unattended for a long period of time, but must be kept from freezing. This type of compounds should be used at temperatures above 55 °F (13 °C) and all of the materials should be a similar temperature.
