Ready-mix joint compound is usually more forgiving than the traditional form 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. Traditional "mix-it-yourself" joint compound usually lasts for one to two hours before drying. However, if it happens to set for more than a few hours than you will need to apply water very liberally as needed to retain its soft texture.
Often referred to as drywall taping mud, joint compound is the primary material used in the drywall industry by a tradesperson, or applicator, called a "taper" or "drywall taper." A similar compound is used in various ways as a sprayed-on textural finishing for gypsum panel walls and ceilings that have been pre-sealed and coated with joint compound. The flexibility and plastic qualities of joint compound make it a very versatile material both as sealer or finishing coat for wall surfaces, and also in decorative applications that range from machine sprayed texturing to hand-trowelled or even hand-crafted and sculptural finishes. In North America the application of joint mud and drywall tape sealer and trowelled joint compound on gypsum panels is a standard construction technique for painted wall and ceiling surfaces. Until more recently in North America, and through the world, several different plasters such as veneer plaster and "plaster of paris" have been used in a similar ways to joint compounds as fillers or for decorative purposes since ancient times, and the actual make up and working properties of these compounds is much similar. Modern ready-mixes or powder and water mixes are available in a wide range of styles from slow-drying to quick-drying to suit specific demands for use by contractors or decorators.