I have a long scratch on my car. The scartch is a fine deep line, possibly made with the tip of a knife. I want to repair the scratch and have tried T-Cut, but this made no difference. I think the best way would be for me to apply a little paint with a small brush. Unfortunaately, the line is much finer that the brushes that I have seen. Has anyone found a good way of introducing paint into a very fine scratch? Thanks A