One reason to prime is if your model is a kitbash with various colors of
styrene/resin, etc.

It is perhaps a little known fact that the undercolor will affect how the
finish color looks. If you want it to be uniform, you should "prime" with a
base color. Light gray is best, but there are occasions when you will want
to use white (e.g. for light yellowsor for a glowing blue), or even a pink
(for warmer reds). Using undercolors can also allow you to sand/scratch
down to that color for weathering purposes.

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Atty Raymond G. Meyer
110 E. Main St
Port Washington, WI 53074
262-284-5566
rgmeyer2@...