Finish coat has rich uniform appearance, with no "high" and "low" spots. Finish resists dirt better and has better scrubbability. One coat of B-I-N kills - that is, covers and locks in even the worst stains that bleed through multiple coats of paint. With B-I-N, there is no bleed-through into the top coat to ruin the job.

This drying compound hardens through evaporation—which means waiting up to 24 hours between coats. Apply it full strength across the joints and at corners for bedding the tape. Then use it full strength or slightly thinned for the top layers. Try to avoid ridges and bumps with all purpose joint compound.