A rough fibre made from the inner bark of tropical plants belonging to the genus Corchorus, especially C. olitorius and C. capsularis. The fibre is woven into sacking and made into jute board, a strong flexible cardboard often used to make shipping cartons. In the food trade, jute sacks have long carried coffee, cocoa, and grain, so their cleanliness directly affects commodity quality — contaminated sacking can taint entire shipments with off-odours. Food-grade jute bags must meet limits on mineral oil contamination.