A good paint job starts before the first coat goes on.(Image: https://live.staticflickr.com/2100/2104958959_91cac944ce.jpg) Interior painters often spend significant time on prep, patch, and prime because walls and trim show imperfections under light. It also helps coordinate walls, trim and doors for a balanced look. Exterior painters focus on surface condition and weather exposure.(Image: https://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Pieter_de_Hooch_-_A_Woman_Drinking_with_Two_Men_-_WGA11694.jpg/103px-Pieter_de_Hooch_-_A_Woman_Drinking_with_Two_Men_-_WGA11694.jpg) A clean finish is easier to maintain when prep and repair steps are done correctly.(Image: https://s0.geograph.org.uk/geophotos/01/77/45/1774500_80c877aa.jpg) When prep, repair and finish work are handled in order, results look cleaner and projects stay easier to manage