My daughter decided she wanted to making something out of wood, and the resulting wagon for toys is being painted with leftover household gloss paint in various colours (mainly by me as it's "stinky"). Since we started painting, she's thinking about decorating on top of the gloss paint with a wide range of colours. So far the project has used solely materials we had to hand, and that means her paints if we want plenty of colours; the best by far are acrylics.
Is there a reasonable way to use these over gloss?
The gloss should be quicker and harder drying than artist's oils, discussed here though I haven't handled the latter for decades. The piece is also small enough that we can warm it to speed up curing (even in an oven, but in full sun the air inside my van can reach 40 °C and it can go weeks without being driven). As this is a kid's project, it's likely to get some rough handling, but doesn't have to last forever. I have water-based varnish (for wood) here, and I've often used oil-based paints over water-based successfully in DIY, but water-based over oil-based less so. oil-based