anyone know how to keep acrylic paints from drying up?

I always store mine, several at a time, in a zip-lock plastic bag and then in a tightly closing plastic box. They all dry out eventually, but keeping them in plastic helps. You can also add a tiny bit of water to each bottle before you store it, then shake it when you want to use it.

Best of luck.

Acrylic paint is water soluble, try adding a little bit of water to reincarnate them.

Make sure the lids are on air tight. They should never dry up it the lid is closed air tight.