Touch-up paint can mask key marks, chipped paint or scratches from minor accidents, but how well your touch-up job looks depends upon your blending skills. Learning how to blend in automotive paint patches will save you money on expensive car repair and professional detailing.
Wash your car with warm soapy water, scrubbing down the affected areas with a clean rag. If you don't take the time to remove grime on your car before you paint, you will never be able to properly blend the new paint with the old. Dry your car thoroughly before continuing.
Mask any areas that you do not wanted painted using masking tape and newspaper. This may include windows and tires in addition to undamaged areas of the auto body. In order to blend the new paint with the old, paint over a small amount of the undamaged area in addition to the affected area. Three extra inches should allow you to properly blend the coats together.
Spray touch-up paint on the affected areas in a colour that matches your car's colour. Wait the indicated flash time, which is the time it takes for one coat of paint to dry. A typical flash time is 15 minutes. After one coat has dried, add another coat. Continue adding coats in this manner until you can no longer see the damaged area.
Leave the paint to dry overnight.
Fill a bucket with water and soak 1,500-grit wet sandpaper into the bucket. Remove the wet sandpaper and sand the newly painted area, working in long strokes. Do not allow the area to dry; you want to apply the sandpaper to a slick wet surface. As long as the sandpaper is wet, you should have no problem working in this manner.
Rinse the area and inspect it with a flashlight. If you still see a difference in the paint colours or if you see paint layers or build-up, repeat the wet sanding process with 2,000-grit wet sandpaper. Rinse the area again.
Rub cutting paste into the newly painted area with a clean cloth, working in small circles. Apply as much of the cutting paste as you need to cover the area. Cutting paste sands off a tiny layer of paint and restores the shine to the paint job; this step will blend your old and new paint together.
Rinse off the cutting paste. The new paint will now be indistinguishable from the old.