This article is from the Miniatures Painting FAQ, by Brenda Klein firstname.lastname@example.org with numerous contributions by others.
Yes. Primer not only assures for good paint adhesion, but it also
brings up detail more starkly than on an unprimered miniature.
Now that that's settled, we go into another major area of controversy
among painters: how? The only thing painters seem to agree upon is
that a spray primer is best, and the primers specifically formulated
for miniatures are better at retaining detail. Some folks use Krylon
with very good results, but it takes a light and even spray to retain
Companies that put out good spray primers are Ral Partha, Armory,
Floquil, Model Master, Testors, and Citadel. Krylon is the best of
the non-hobbyist primers, but other store brands are in the same
league. If you use sandable primer, be especially careful to use
thin coats so as to not obscure detail. (Many department stores
and most home improvement centers carry spray primer at much lower
cost than hoby and other specialty shops.)
BEFORE APPLYING PRIMER you will need to clean up any bad lines on
the miniature (use a small file, X-acto knife, or emery board),
making sure you get rid of the bump under the base, if your miniature
has a self-molded base (sandpaper is excellent for this), then
WASH it in a little soap and water. Various substances are used on
miniatures to make them come free of the mold, as well as the fact
that hand oils get on the miniature as it's handled, and these will
interfere with paint adhesion unless cleaned off. Now, use a little
white glue (or rubber cement - thanks Ed Sharpe!) and glue the miniature
to a base of cardboard, cork, wood strip, popsicle stick, ruler, plastic
bottle cap... Anything you can safely handle without touching the
figure. This assures that you can handle the miniature during the
painting process without touching wet paint. Even a freshly dry coat
will rub off without the slightest provocation.
Methods of applying primer are spraying and brushing on. If you're
using a brush-on primer, make certain it flows well without being
too thin and use a semi-large brush to brush over your miniature from
top to bottom.
If you're spraying, set up a large box enclosed on three sides in
which to place your miniatures for priming. This will keep the paint
from going everywhere and also tends to give a better coat. Make
"sure" you have good ventilation, outdoors or in a window or set up
a fan. Spray paint is nasty. On the subject of technique, the best
advice I've seen came from Deep Six (email@example.com), as posted to
rec.games.miniatures, and is edited and used here without permission:
"First, be sure you shake the paint well. It says on the can you
should shake it for a full minute, so I do it for two minutes.
Shake during use, too.
The second thing is spraying the figures with the `good' stream
of spray. You do this by starting the spray before it hits the
figs and stopping the spray after it hits the figs. The spray
that comes out of the can when you first start spraying and when
you stop spraying is incomplete -- it has too much or too little
paint, and/or too much or too little carrier. What I do is put the
figs out on newspaper and start spraying the newspaper to one side
of the figs, when the spray has been coming out for a half-second
or so, I pass the spray over the figs, and when the spray has
passed over the figs, I stop. This assures that only properly
mixed paint is falling on the figs. It takes longer and wastes
some paint, but the finish is worth it to me.
Next, keep the can as upright as possible, and keep the nozzle
about 10 inches from the figs. Any closer and it's too hard to
control the amount of paint on the figs. Any further and the paint
starts to dry before it hits the figs.
And finally, IMO you should never use a whole can of paint (on figs
anyway). It seems like when the can is about 3/4 of the way empty,
the paint is really crappy, uneven and it comes out of the can in
And Coyt reminds us to always make sure you get the underside
of the miniature as well, particularly if it's a figure in a cloak
or the like. Spray upward and at an angle and make passes from
all sides to assure coverage.