Shoot for close to flush; say less than 1/32" higher than the bottom of
the cabinet. Perfectly flush is a mark of attention to detail and some
cabinetmakers make the FF flush with the bottom as a matter of course.
Others leave it a bit higher.

David

damian penney wrote:

I read in my Building Kitchen Cabinets book that the face frame should
be aligned so that it's flush with the inside bottom of the case.
However looking around Home Expo all their cabinets have about a 1/4"
lip between the face frame and the cabinet bottom (and it's like that
in our current cabinets). Thoughts ?