Is there a significant difference between primer and paint?
I’m out of primer, but I’ve got a bottle of MM ghost gray enamel.
Thoughts?
Depends on the primer. Some primers have more “tooth”. They eat into plastic a bit more than enamels or acrylics, and give better adhesion. Also, some primers are very full-bodied, contain a LOT of solid material to fill small scratches from sanding or filing.
Lastly, some primers act as a good shield between the plastic and very hot paints like lacquers. Some people paint model cars, for instance, with automotive lacquers, and primers may be needed for that.