I've got a few rusty spots I need to touch up. I've rubbed off the flaky paint and applied rust killer. Now for paint. The colour is metallic maroon. I have a jam jar of paint from the body shop. It was left over from the last proper paint job the car had. I've done a bit of testing on some scrap metal and it seems very fifficult to apply the metallic bits in the paint. Most of the time they stick to the brush and the result is non-metallic maroon. The only way to get the metallic bits to come off the brush is to blob it on very thick, which is a problem with vertical body panels. What can I do? Is proper touch up paint thicker and better at keeping the metallic bits in suspension?