Home builders typically use joint compound to finish drywall panels because it is inexpensive and easy to use. Some builders, however, opt for the durability and distinctive finish that only plaster of Paris can provide.
Workers use joint compound and paper drywall tape to finish the joints where panels of drywall meet. Plaster of Paris is suitable for covering either wood lathes or specially treated drywall panels.
Joint compound is available in both powder and ready-mixed form. Plaster of Paris is available only as a powder. Both powder products require the addition of water. The ideal consistency is similar to that of toothpaste.
Joint compound is easy to work with, so it is the best choice for first-timers. Working with plaster of Paris requires considerable skill and experience, but it is more durable.
To identify what type of finish your home's interior has, scratch a surface with a coin. Joint compound is easy to scratch. Plaster of Paris resists gentle scratching.
Finishing with joint compound requires a selection of flat drywall knives. Plaster finishing requires several kinds of trowels.