Vegetable parchment is made by passing a base sheet through concentrated sulfuric acid, which partially dissolves and then re-gels the cellulose fibers, creating a dense, grease- and moisture-resistant structure. This acid-treatment process — not a coating — is what defines it as parchment and distinguishes it from greaseproof paper (which is supercalendered) and silicone-coated release papers (which are classified elsewhere as coated papers).

Glassine is defined by its high degree of supercalendering, which produces a smooth, dense, air-resistant sheet with specific Gurley porosity values, while tracing paper achieves transparency through a different manufacturing route (often involving resins or heavy beating). Mill specification sheets showing porosity, density, and manufacturing process description help customs filers distinguish between these grades and support the correct classification within SITC 64153.