Recommended custom brush resolution

[MrMiracle77]

I'm at work, so if the answer to this is already available in tutorials or documentation, I apologize.

Is there a recommended brush resolution? I know that brush lines can increase render times, but if the brush is kept small then the impact may be reduced (I hope). 64x64 pixels, for example?

[slowtiger]

Just open some of the existing brushes to get an idea.

[Greenlaw]

I'm not sure there's a size limit. I've made brushes at 512 and 256 square. I'm sure you can go smaller.

Chucky's the expert on this topic so hopefully he'll pop in with some better info.