Hi,
First time woodworker. I built a cabinet out of furniture-grade
plywood, which I edge-joined 3/4" oak to, to give a finished edge on
all sides. It also has a pine decorative board on top, with oak and
cherry appliques glued down, and it's trimmed with urethane dentil
molding.

It came out nice - but now I want to paint it in an antique white
enamel. Since it is made from a bunch of different materials, I want
to make sure I prime it the right way for the finish coat. I'll be
using a spray gun with a pressure cup, which has given me good results
with heavier viscosity paints (like enamel) in the past.

So, what is the best sealing/priming material to spray on first?
Someone suggested "white shellac". I want something that will give a
good leveling undercoat, which will hide the various species of wood,
and give a nice consistent surface for my finish coat.

Any recommendations as to the best stuff to use would be appreciated,
thanks.

-Randy