I figured out a little trick that makes it real easy to spot those bubbles.
Use some light source, such as a bright flashlight, to back light the part
from the opposite side from where you are inspecting for bubbles. You don't
need a lot of the light to come through the part. If almost any of the light
is able to shine through, and usually this is the case, the bubbles light up
more than the surrounding lay-up. Even the very little bubbles become
incredibly easy to spot.

I will have to try your roller idea. Seems like it would be easy to clean
after each use.

Don Parsons