Paint or acrylic

There are three primary types of paint in use when it comes to plastic modeling; laquer, enamel, and acrylic. The primary differences, from a usability standpoint, are mainly between enamel / laquer and acrylic. I tend to lump laquer and enamel together because they have a lot of similarities from the perspective of building plastic models. They are chemically different, and laquer is more "Aggressive" than enamel, but they are similar enough in how they behave.

Acrylic has the distinct advantages of being virtually odorless and it cleans up with water. It doesn't adhere to plastic as well as enamel or laquer, and unless it is allowed to cure thoroughly painting over it can cause problems. It also dries to the touch very, VERY fast. I have a hard time brushing acrylics simply because they dry so fast; the paint will dry on the brush and whatever I'm using for a palette before I get a couple of passes done.

Enamel and laquer, on the other hand, are pretty noxious to spray. Handling the fumes can be a problem. Laquer is just plain evil. I don't use a respirator when I airbrush acrylics (although I should) but I do when I spray enamel. I avoid laquer like the plague these days, I had enough of that stuff to last me forever back when I was paint R/C car bodies. These two tend to adhere to the plastic better, and when fully cured have a much harder surface than acrylic (acrylic, after all, is a form of plastic). Painting over enamels is seldom a problem.

Personally I use mostly acrylic for airbrushing. I like being able to clean up with water or mild solvents (I usually use MikeV's solvent recipe of 2 parts distilled water, 1 part Simple Green, 1 part Windex), I like not having a basement full of paint fumes, and when airbrushing I like having the surface dry about the time I put the airbrush down. If I am going to paint over it with another color I'll usually spray a light coat of Future over it first.

If I am going to hand brush something I'll usually use enamel though. The super quick drying feature of acrylic just really gets in my way when trying to use a brush.

I'm sure other people will have more comparisons, but those are the ones that come to mind for me.

Man, you just asked a mothful. I'm afraid I can't provide nearly as lengthy an explanation as MusicCity, but I'll tell you what I know.
Acrylics are generalised as paints that can be cleaned up with water. They adhere to plastic very well, and are great for airbrushing whatever you build, be it armour or aircraft. Also, there is a very wide selection as Model Master offers acrylics, Humbrol, and of course Tamiya, who'se entire most popular range are all acrylics. They're absolutely great.
I use acrylics EXCLUSIVELY when airbrushing, because I can just use a little bit of Windex (advice from this forum) to clean the nozzle afterwards, and just flush clean with a little bit of water.
I don't know anything about lacquers, except that they are similar from a modelling perspective to enamels. I never airbrush them, as you will definitely need a vented space (airbrush booth) a full respirator and a number of other safety devices. THe stuff is just plain dangerous to inhale. I do, however, use it on a regular basis for hand-painting.
Both are paints that you should use if modelling, but for airbrushing, I say go with acrylics

Acrylics can be problematic in an airbrush. Pigments tend to be coarser and coupled with quick drying times, can clog an AB quuickly. Andrea/Vallejo are the tops when comes to acrylics. The only acrylic I've had a problem brushing over is Tamiya. THeir line is absurdly limited in colors for a modeling company and literally can't be brushed and don't work that well in an AB eeither.
Enamels are solvent based and have excellent AB properties.
Laquers are mostly the realm of car builders who will ofetn airbrush automotive laquer for their high gloss and superhard surface.

Wow you are really asking a lot of technical stuff. It depends on whom you ask. To a modeler, acrylic means water soluble, and enamel and lacquer mean solvent based, but that is not what a paint specialist will tell you. You will see both acrylic enamel and acrylic lacquer used. Acrylic used along with enamel seems like an oxymoron.

You can classify paint according to the kind of carrier used, either water or solvent based and also on how the paint dries (cures). Lacquer paints dry when the solvent evaporates. When the dried paint comes in contact with solvent again it will slowly turn back into paint. Enamels cure when they dry undergoing a chemical change.

There really is no "best" for models. They all have their advantages and disadvantages. It's a trade off you have to look into. Car modelers seem to prefer lacquers as the best finish. Acrylics (as in the modelers usage, and not as in acrylic lacquer as in painter usage) don't seem to give the gloss finish compared to enamels/lacquers(acrylic lacquers).

QUOTE: Originally posted by ajlafleche Acrylics can be problematic in an airbrush. Pigments tend to be coarser and coupled with quick drying times, can clog an AB quuickly.

Actually many acrylics have finer pigments than enamels.

Mike

I use Gunze acrylics from my AB, and I get a very fine finish indeed, every bit as good as enamels.

Karl

The problem with acrylics clogging up airbrushes isn't the pigment size, but rather the very fast drying time of acrylics vs enamels. Hobby paints for models doesn't help either as they are highly pigmented. Maybe denser was the word ajlafleche was thinking of instead of coarser but that applies to both acrylic and enamel hobby paints.

Tamiya and Gunze don't seem to have the clogging problems associated with other acrylic formulations. They seem to be so much different. Acrylics seem to have a much wider set of properties across formulations compared to enamels.

In line with what hungfarlow wrote above, I have found that Gunze gives a finer finnish than Lifecolour, suggesting perhaps slightly finer pigments.

However I have also found that choise of thinner has an effect on not only finish, but final colour tone. Both Gunze and Lifecolour give a 'coarser' finish, fine for armour, when thinned with distilled water, but an extremely smooth finnish when thined with Tamiya acrylic thiner.

Karl