just repaired a 3' x 4' area of a sheetrocked ceiling - now I need to paint the area - I have finished mudding the area and am ready to paint - my question is how do I blend in the new paint with the existing since the existing is 10 years old and this is in the kitchen - the ceiling is white and clean. Any tips on how best to fether it in so I don't have to repaint the entire ceiling? Thanks