Interior and Exterior Paint Components

Paint manufacturers dream up every color under the sun, but they also make products for specific jobs and environments. Paint for interior projects is designed to hide brush and roller marks, resist staining, allow cleaning and withstand mildew.

Interior paints don’t need to cope with sunlight or harsh weather, so they contain few additives. Exterior paints must combat UV rays, fading and other damage, so they have many extras.

Resins

Resins are the binder that binds the pigment and solvent together in paint. They are important for both interior and exterior painting as they provide the final look of the painting and help resist fading, mildew and other environmental factors.

Since exterior paint is exposed to huge temperature changes and moisture, it needs to be flexible enough to handle those conditions without peeling and chipping. This is why the resins in exterior paint are a bit different from those in interior paint.

The resins used in interior paint, on the other hand, are designed to be scrubbable and washable while reducing the amount of volatile organic compounds it contains. This is vital for preserving air quality in homes, as these chemicals can be dangerous if inhaled. The resins also allow for a smoother finish to reduce the risk of scuffing and smearing when applied. This is especially helpful when working with detailed surfaces or textures.

Additives

While all paints have the same basic components (pigments, solvents, additives and resins), different kinds of paint have additional capabilities that make them suitable for particular environments. For example, interior paint is engineered to be scrubbed and cleaned while exterior paint needs to be able to resist fading from UV rays.

Manufacturers also use different binding resins for each type of paint. The resins bind the pigments and other ingredients together and also affect how quickly the paint dries and the color fades over time.

Paint additives can make a big difference for DIYers as well, saving them from the frustration of wasting paint and having to buy more when they run out halfway through the project. They can also help tweak store-mixed colors to get just the right hue, like a little more yellow in burnt umber or more cream in raw sienna. The best additives for indoor paint are fungus and mildew resistant and low VOC, which reduce the amount of ozone-depleting chemicals released during the drying process.