Paint - Lacquer vs Enamel?

It's all in the carrier... Enamels use (typically) mineral (white) spirits or paint thinner, a more generic name here in the States - they are essentially the same. Lacquers use, not surprisingly, lacquer thinner as a carrier for the pigments in the paint. IIRC, nitrocellulose is the name for lacquer used in Great Britain. Now, to confound things further, you can use lacquer thinner to thin (reduce) enamels though you cannot use mineral spirits to reduce lacquers. Two different animals. All of this is of some benefit to we modelers. You can lay down a lacquer paint and use an enamel over it without worry of the successive layer attacking the previous coat. You can then use an acrylic on top of the enamel for the same reason. This is helpful if you can only find given colors in certain paint ranges. You want to lay the 'hottest', i.e., most volatile thinner-based paint, down first. I'm not certain why these formulas developed but drying time is an obvious offshoot/benefit. Lacquers are very fast drying, followed by enamels and then arcylics. Toxicity is another thing to consider. Acrylics are considered the safest or least harmful.

Acetone is yet another useful carrier/thinner/reducer as is evidenced by nail polish. Typically, nail polishes are too thin to cover well as they're designed to be applied thickly, hence the brushes in the bottles. You can reduce and airbrush them but they're not very opaque. To use them over different colors can offer some neat effects, though.

Frank Kranick

Both lacquers and enamels contain pigments and vehicles. The enamel vheicle undergoes a real chemical reaction when it dries (the solvent evaporates). The lacquer dries with the solvent evaporating vehicle doing a simpler reaction, and the pigment particles kind of "stick" together. The solvents in lacquers are usually "hotter" than those of enamels, and may affect the plastic more. Indeed, acetone is one of the possible lacquer thinners (there are several). Also, nail polish used to be a lacquer- don't know about modern ones.

The above is true for older, non-acrylics. Acrylics are another thing all together, and there are both acrylic enamels and acrylic lacquers. I find it a bit difficult understanding the chemistry of acrylics, personally.

Lacquer (cellulose) thinner is a great vehicle when spraying. It keeps the paint thinned as it goes through the airbrush, but - if applied carefully and NOT allowed to 'wet' the surface, will evaporate before hitting the surface. Otherwise it will eat the plastic. Acetone, though slower acting, will do the same. White (mineral) spirit is safe on plastics, and is a good degreaser/cleaner also

Chek

Depends on the paint. I have had hobby enamels that would not coexist with lacquer thinners- it curdled the paint. So always test small batches.

Personally, I use Testors enamel a lot. While I use store paint thinner to clean airbrush and other cleanup, I have never been able to find a thinner that works as well as their own enamel airbrush thinner. I buy it in halfpint cans, and since I ONLY use it for thinning for airbrush use.