For my next cheap trick I shall make the cracks in my decals (almost) disappear. The darkest, nearly black decals have cracked and shrunk in the last 9 years.
All you need is a little patience, and an
oil based paint pen you can get at any craft store. The sales lady will try her darndest to sell you a magic marker. NOT. They will only make purplish lines, not black.
And it looks better in real life than in the pics. Even better from 2 sites away.