Unisaw A100 wrote:
In the architectural woodworking industry (the
business I'm in) we shop finish everything. It's
anything but substandard.

http://www.awinet.org

UA100

I dont care what industry it is. Unless you have a way, in the field,
to pull the casing/trim _dead tight_ against every millimeter of its
length along the mating surface you will be left with small gaps which,
as I stated, to me make for a substandard end result.
When applying almost any trim to even the best skim coat plaster job,
wood, metal, whatever, there will be inconsistancies in both the trim
and the wall which will make for these gaps. They are especially
undesireable with light colors as they show like a sore thumb. They are
even worse when the trim is not caulked and in time the joints open up
leaving a tiny jagged edge where the paint failed to bridge the tiny crack.
Unless you have a way, and desire, to fasten the trim every couple
inches, "sucking" a piece of trim in dead tight along its entire length
is a very rare instance, at least it was for us and in time it may open
even if you got it tight on instal. Perhaps your millwork is shop
finished, then the painters who mate up to it in the field caulk the
gaps you leave when finished. I would venture to guess they do.
Perhaps you have someone hand plane each piece of trim to meet the
inconsistancies of the wall and the trim itself, I dont know. For us the
bead of caulk provided a tight finish with very little time and effort.

Mark