Leenia - The artist paints we've used have been labeled as Latex and/or Latex-Acrylic. There's a slight difference between the two, but not enough to matter much.

Some of these are available in "pens" for marking or touch-up, but for any significant work the pens aren't an ideal way to "paint" artistic work on. A brush and palette method works much better.

Watercolors of course don't work too well since they don't stand being wet. Artist Oils may get "dry to the touch" in a few days but don't "cure to the bone" for years (or decades).

For changing the color of the whole case, I'd recommend an aerosol can of acrylic/latex enamel, if only because it's much easier to get a smooth coating with a spray than by brushing. In the US, almost any of the "RustOleum" ® brand enamels should be okay, perhaps with a slight preference to one of engine or implement types you'd use to paint your tractor.

Many cases have a "plastic" skin of some sort, and the original covering may have residual mold release or other "unsticky" surface treatments, so the plain water based latex paints may not get as good a "grip" as the "machinery" types.

"Painting" is a little ambiguous. You may want to:

1. Change the color of the entire case, just because
1.a. You like a different color
1.b. You want a good background for painting your own artwork on it.
1.c. You want a uniform surface for sticking things like decals and/or bumper stickers on.

2. Just add your own (painted on) smart-assed comments, or stick-on labels.

My own "home made" banjo case was built up with the "curved parts" mainly out of the heavy cardboard stripped out of a bunch of old 3-ring notebooks. Sides were "heat bent" to exotic curves, but the experience did not indicate that cardboard is a best choice for "formed parts." It worked okay, but the bending is much more difficult than with good wood. Top and bottom surfaces were flat plywood. Unfortunately it's almost impossible to find wood (or plywood) thin enough in my local market so the case is about as heavy as the banjo.

The whole thing was spray painted a lovely bright yellow, and "artwork" applied with what amounted to a "decoupage" technique to top and bottom. Decorations on the lid were "popular art works" but on the bottom I used quite distinctive "classic paintings"¹ for variety.

1. "classic paintings" means 15th thru 19th century naked ladies, so I do try to keep the case "right side up" when children are present.

It's unique and distinctive. Now if I could lift it with the banjo inside it would be just about ideal. (It is heavier than intended.)

Lin painted "original artwork" on our plastic sided camper, using blow-ups of pictures stolen off the web. Enlarging a 3" square picture to 30" x 30" isn't easy, but I managed to get something good enough to guide her with where to slop her free-hand versions on without making them look like tracings. We used the same "artist paints" on the camper as above.

John