Heading 6502 covers plaited hat shapes that are still unfinished — not blocked to shape, not fitted with a brim, not lined, and not trimmed. Once any of those finishing steps has been applied, the article moves to heading 6504, which covers finished or semi-finished plaited hats and headgear.

No — heading 6502 is material-neutral. The defining criterion is the construction method: plaiting or assembling strips. Whether the strips are of straw, rattan, synthetic material, or paper does not change the heading, though it may affect the applicable duty rate at the subheading or tariff-line level.