These creams are unbelievably effective and, in particular, the "step 1" can literally do miracles on scratches. I completely removed very deep scratches - that I never thought would go away - in a breeze, literally. Words can hardly express how enthusiastic I am about them.

However, these creams are intended for thick polyurethane/nitrocellulose coatings. As the creams are white in colour, they tend to creep visibly into any crack of the coating and are hardly removed from thin hairline cracks. As shellack lacquer finishes tend to leave the natural grain and pores of the wood more or less exposed, I suggest that these creams are first tested in a small (possibly hidden) area. I also ignore if they would react with shellac in some way; I tend to believe that they're quite safe, but again I would recommend testing them first in a hidden area.