Compared to other trims like plaster cornices and even plaster coving, polystyrene coving needs to be changed more often. Read more: 16 Drywall Alternatives That Will Look Just As Good In Your Home.

3. Size and Proportion. Large rooms can accommodate wider coving, which adds a grand and balanced effect. In smaller rooms, narrower coving can create a more delicate and proportionate look.

If you have stripped your coving back to plaster, I recommend applying a primer before you begin painting. This provides a stable surface that the new paint can adhere to.