I can see some of you nodding in agreement at me now.
And others going 'Huh? The dreaded what bleed?".
Tannin bleed. The yicky-yucky, browny-yellow, pain-in-our-butt stain that comes through when painting bare red-woods such as mahogany and cedar.
And what is tannin you ask? (You probably didn't ask, but I'll tell you anyways).
Its an acid in the wood that is water soluble so when you add a water-based paint onto the surface the tannic acid rises to annoy the heck outta us.
This is especially annoying when you've already started to paint and then have to re-do. But if you realise it in time you can save yourself a lot of extra work by using a stain sealer first. Zinseer BIN is a good one, or a shellac based sealer.
We are currently trying to develop a sealer/clearcoat (as part of our Vintage Paint by Voodoo Molly range) which will help to control the dreaded tannin bleed. Fingers crossed we can nail the formula soon.