0. Different paints have different properties, and are formulated for different purposes. Interior paint is made to be scrubbed, resist staining, and allow cleaning. Exterior paints are made to combat against fading and mildew. When starting a painting project, it’s important to know the differences between the two and choose the right paint. In order to understand the difference between exterior and interior paints, you will need to learn a bit about the chemistry behind paint. Read on for an introduction to the main components of all paints.