The common defects in paints are: 
    1.    Blistering and Peeling: Blistering and peeling are defects in which swelling of the paint film occurs caused by the formation of an air bubble under the paint film due to the presence of moisture or oil or grease matter. If it is due to moisture then it is called peeling and if it is due to oil and grease matter then it is called blistering. 
    2.    Fading: Fading is the discoloration of the paint surface due to atmospheric agencies such as sunlight, and moisture. 
    3.    Grinning: The visibility of the background due to insufficient opacity of paint film even after the final coat is called grinning. 
    4.    Chalking: Chalking is the formation of powder on the painted surface. This is due to the use of insufficient oil in the primer. 
    5.    Flaking: The detachment of paint film from the surface is called flaking. It occurs when the bond between surface and paint film is poor.