AllSeeingSkink wrote:
If I'm using one of my really good brushes that I want to last, I use 2 brushes to paint. One for mixing and thinning (a crap one) and the other just for painting (the good one).

Make sure the good brush isn't soaked in water when you go to dip it in to the paint. So when you occasionally have to rinse off the good brush, don't dip it straight back in to the paint but wipe off the excess moisture on a tissue first. That keeps the body of the brush drier and stops paint wicking up it.

So basically keep the brush (relatively) dry and the paint wet (using a crappy brush you don't care about).

That's what I do with my fine detail brushes and it mostly seems to work. Occasionally paint will still get up there, but it happens less often, for example the other night I painted for about 1.5 hours with my Raphael 8404 4/0 and didn't get paint in the ferrule until right at the end (basically when I got lazy and overthinned the last of the paint on my palette instead of just mixing up some more).

But if you're doing glazing or washing or techniques that use super-thin paint, the paint is going to be so thin that wicking up the brush is inevitable, so for those jobs I don't use my *best* brushes, but just some cheaper kolinsky brushes. A few companies make cheaper kolinsky brushes (I assume made for the arse hair rather than the tail hair that the expensive ones come from) that are better than synthetics but cheap enough that I don't care if I get paint up in the ferrule (though I still wash it out with soap and water as best I can).