Shellac is a refined form of lac—the resinous secretion of the Laccifer lacca insect—and is classified under heading 1301 in the residual subheading 130190 for natural gums, resins, and balsams not elsewhere specified. Shellac-based varnishes or preparations that have been compounded with solvents may shift to a different chapter depending on their formulation.

Gum arabic is specifically named in subheading 130120 and covers the dried exudate of Acacia senegal and related species. All other natural gums, gum-resins, resins, and balsams—including frankincense, myrrh, dammar, and copal—fall under the residual subheading 130190. The botanical source and whether the product is specifically gum arabic determines which subheading applies.