Tojo72
You can use Post-it notes to mask adjoining panels.Some modelers use Friskit Film,it's a sheet of plastic that labs use to seal the tops of test tubes.
Tojo, did you mean Parafilm? I know it's original use was for sealing lab equipment like beakers, jars and tubes. I think frisket is used more by artists, iirc. Have a great day!
Gary