How To Keep Mold From Ruining Your Paper Mache • Ultimate Paper Mache (2024)

Today’s video is about mold, and how you can keep it from ruining your paper mache sculpture.

Here’s the short version: It’s all about the water! Mold can’t grow without water, so the way you can keep mold out of your paper mache is to:

1. Use the fewest layers of paper and paste or the thinnest layer of paper mache clay that you can get away with. I use no more than three or four layers of paper and paste, and sometimes use less. When I use paper mache clay, I spread 1/8″ or less with a knife over the armature. (You can add more paper mache clay after the first layer dries, because it isn’t very absorbent).
2. Put your sculpture where it can dry quickly – in front of a fan, over a furnace heating vent, or outside in the shade on a warm day. You can dry it in an oven if you need to, at around 200º F.
3. Never paint and seal paper mache if there’s any moisture left inside.
4. When it is totally dry, seal it so it can’t absorb moisture from the air.
5. Display the sculpture (or store it for next Halloween) in a dry place, the same sort of place where you’d display or store an original watercolor painting.

I have a house full of paper mache sculptures, and none of them have ever developed mold. I don’t do anything special to protect them, except for following the rules shown above. Folks who live in the tropics may have to take different measures, but for the rest of us, drying the piece quickly and keeping it dry will help it last for a very long time.