What is a common cause of paint blisters?

Paint blisters typically occur when moisture becomes trapped under the paint layer. This can happen if the underlying surface is not properly dried before painting or if there is humidity in the environment during the painting process. When the paint is applied, the moisture tries to escape, creating pressure that forms blisters on the surface.

While poor surface preparation is a significant factor in paint adhesion and finish quality, it doesn't directly cause blisters like moisture does. Low-quality paint may lead to other issues, such as poor adhesion or fading, but it is not the primary culprit for blistering. Excessive heat during application can negatively affect the curing and drying process of the paint, leading to wrinkles or uneven finishes, rather than blisters. Therefore, the presence of trapped moisture is the key factor in explaining the occurrence of paint blisters.