Interior vs Exterior Paint: What’s the Difference Between Them?

The difference between interior vs exterior paint is in the formulation. Interior paints need to be interior painters san diego durable and scrubbable for easy cleaning within your home. In contrast, exterior paints need weather resistance and protection against UV rays to maintain long-term coverage on the outside of your home. Fortunately, Real Milk Paint bridges the gap when you mix it with Outdoor Additive to create versatile interior and exterior paint.

The Differences Between Interior and Exterior Paints
Most paints contain the same main components: pigment, resin, solvents and additives. For example, oil paint manufacturers typically use mineral spirits as a solvent, while latex paint manufacturers use water. The main difference between interior and exterior paint, however, comes down to the binding resins. The binding resin in exterior paint is softer to better resist fading, peeling and chipping. In contrast, the resin in interior paint is more rigid to reduce smearing and scuffing.

Interior Paint: Composition, Properties and Characteristics
Interior Paint Composition and PropertiesEven though interior paint is more delicate than exterior paint, it holds its own regarding volatile organic compounds (VOCs). Indoor paint typically has much lower VOC concentrations, and some paints, including Real Milk Paint, have no VOCs at all, so you can paint indoors without worrying about needing extra ventilation. Likewise, water-soluble interior paints typically don’t contain fungicides and offer a more comprehensive selection of finishes, from matte and satin to gloss and semi-gloss, than their exterior paint counterparts.

While exterior paint colors are basic, interior paint colors run the gamut from soft and subtle to bold and bright. Organic pigments in indoor paints such as Real Milk Paint and all-natural ingredients, including milk casein and lime, provide versatile colors that are safe for use in homes with kids and pets. Many indoor paints are also stain-resistant for easier cleaning. Keep in mind that while you can use exterior paint indoors, it requires more ventilation and drying time to cure. Even without exposure to sunlight, most interior paint dries quickly.

Exterior Paint: Composition, Properties and Characteristics
Exterior paint is specifically formulated for outdoor environments because it must handle extreme temperatures and be flexible enough to withstand significant temperature changes when warm weather suddenly becomes cold. The binding resins within exterior paints let the coverage expand and contract without peeling and chipping. Additionally, additives help it resist staining, mildew and fading. You can even combine interior paint with Outdoor Additive by The Real Milk Paint Co. to transform it into a durable exterior paint.

Another difference between interior and exterior paint is adherence. Outdoor paint has a formulation that promotes better coverage on rougher surfaces. Unfortunately, snow-, rain- and fade-resistant exterior paints usually contain more VOCs than interior paints, so you don’t want to use exterior paints inside except in highly ventilated areas. On the bright side, oil-based paint manufacturers are phasing out this type of paint due to the higher VOC emissions.