Should I use paint to lawn ornaments outdoors?
Halloween decorations I plywood and paint. Should I use exterior painting, as it is a kind of face? Or I can use acrylic paint and then sprayed with polyurethane outside?
Acrylic is very good, no need to use house paint. Most is impermeable to water, but the polyurethane can not hurt. You can prioritize the wood absorbs less than the paint color, the color affected by wood, etc, but it all depends on how you want it to look good, and the time you want to last.
Outdoor Halloween Decorations-HGTV