Size of touch up area. If there are several spots to be touched up or if the area to be touched up is large, repainting from corner to corner is the better choice. A large area is difficult to feather in and match the texture. If there are several spots to touch up, it is very difficult to treat all the spots exactly the same way.
Touch up using the same paint (and same batch number preferably) that is on the surface to be touched up. If the paint product is different from the paint on the surface, the touch up is likely to show. It is not only important to have the same paint, but having the same batch number will increase the success of the touch up as well.
Ensure the paint and the surface are clean and free from contaminants. If the paint or surface has been contaminated in some way, it will affect how the paint matches and blends into the surface.
Use the right tools and techniques. The best tool for touch up is a clean, dry brush.
- Latex – Using a minimum of material, first fill the imperfection then feather the paint into the surrounding area, using the bristles of the dry brush to match the texture of the surface.
- Oil/Alkyds – Just touch the paint to the spot and let it flow out, otherwise it will flatten and cause a milky halo.