I put on a little bit, let it soak up for a few minutes, then squeegee off all of the excess. That way the wood seals up and doesn't pull the resin out of the glass.

My guess, for what it's worth, is that when only a little bit is put on to seal the wood, the wood will absorb less resin than when it can continue to pull the resin out of the cloth during an entire cure on unsealed wood. Just a guess, I'm not trying to start a flame war.

Dale