ABS = acrylonitrile butadiene styrene.
An industrial plastic.
I buy a 1/16" thick white sheet of this material, glue it to plywood using countertop cement, sand it until it looks like a lovely piece of matte ivory, and paint away. No priming necessary. It is archival.
A great alternative is to buy a gesso panel here.
http://www.realgesso.com/
These panels are primed with gesso -- not the acrylic stuff, but the real thing.