A product classifiable under 3814 must be a mixture of two or more solvents or thinners. If the article is a single, chemically defined compound (even in solution), it belongs in Chapter 29. The key test is whether the formulation contains multiple distinct solvent components intentionally blended for a combined effect.

No—the heading's single six-digit subheading (381400) covers both composite solvents/thinners and prepared paint or varnish removers together. Importers should ensure the product description on entry documents accurately reflects which function the product serves, as end-use can affect admissibility under EPA or state VOC regulations.