So, is it curing or something?
.
Yes and no.
It was feeling pretty hard and I started sanding a few areas to see if it was dry all the way through and it was dry enough. Not 100% but close enough to sand well.
Anyway, the sanding revealed a few flaws in my prep in some areas. The exposed end grain on the sides of the body had sanding scratches in the wood that I didn't see before I started painting. Also, the shellac was not looking right on the end grain. Certain rings in the board had taken on a peculiar shade of green-ish something or other. It wasn't good.
Also sanding scratches on the neck.
So, I ended up sanding those areas back bare again to correct the scratches in the wood grain. This time I went up to 800 grit and steel wool to work them clear.
I decided to skip the shellac on the stripped areas. The sides look much better and the neck looks fine.
I left the shellac on the figured top and the headstock face so from the front, it all looks the same. Only the back and sides were changed. And the changes were subtle. I didn't have all that much shellac on them anyway. Just enough to fill the grain and leave a thin film on that.
So, I had to re-lacquer the sides and neck so I'm waiting now for that to dry.
A minor setback but frustrating and completely avoidable. Shame on me for not being patient.