Aves and Milliput can likewise be water-thinned and sculpted before they set. Great for working into cracks and then taking a wet knife blade or spatula to smooth out and minimize any sanding. I like using it a bit more on larger gaps (deck edges).
All sand well if you want to go the traditional sanding route.
: Although I'm sure this question has been asked
: and answered many times, what do you
: recommend as a seam filler for plastic
: Art Rohloff
: West Chicago, IL