>>9873988So I've painted a fair few of them. I don't have a guide but here's my personal tips.
1. Wash it. Blanks often have mold release on them which will make paint flake off or go on strangely. Soap and water works.
2. Take the color of the figure into account. If you lay down green paint on a white figure it will look very different than the paint you lay down on a black figure. Test colors on the bottom of the feet or other inconspicuous places.
3. The US market is somewhat in the thrall of Monster Kolor, but any paint works. Just bear in mind that some paints are more fragile than others. A strong, durable clear coat is a must. If you want a recommendation on paints, I suggest Vinyl Wonder or Mad Ape Ninja. Both are true vinyl paints (Monster kolor isn't). Mr.Hobby Lacquers also work well.
4. Get a spray mask. You'll have the best luck on amazon: thanks to covid everything else is always sold out. Least last I looked.
5. Observe other people's paint jobs. Try and figure out how they did them. A lot of sofubi is painted using relatively simple techniques used in smart ways. Paint rubs, Dry brushing, directional airbrush sprays, etc.
6. I'd recommend an airbrush. The iwata eclipse is the one I use. I painted my first few by hand and an airbrush really is easier. And it lets you create different effects that you can't do, or at least not easily, with a brush.
7. Buy some cheap sofubi from japan to test on. There's tons of ultra man, godzilla, and similar figures out there for a few bucks a piece. They all have high levels sculpt detail and are made of vinyl so they're great testing grounds.