When I texture paint when I repeat and tile brush to get smaller it gets worse? I'm texture painting, I've created a 2048x2048 brush. It's a nice brush, however I wanted to wanted the pattern the brush to create to be smaller. So I repeated in the texture mapping panel and the quality deteriorates.

I'd expect this when I'm making the texture bigger, however I wouldn't expect this to happen when making the  original brush smaller? And ideas if there's a fix to this?
I think that if your target's resolution (image texture being painted on) is low, it will have problems interpreting the projected pixels. If you instead paint on a larger image of at least double the resolution, you will get a better result.

Here I made a 2048x2048 brush, set to repeat like yours and painted into a 4096x4096 target image.