Numbered duck (army duck)
Numbered duck, or army duck, is cotton duck graded on a US scale from about No. 12 (lightest, ~7 oz) to No. 1 (heaviest, ~19 oz). A lower number is a heavier cloth. Each number maps to an approximate weight and a standard 2-ply construction.
Approximate weights: No. 12 ≈ 7 oz (230 g/m²), No. 10 ≈ 8 oz (270), No. 8 ≈ 10 oz (340), No. 6 ≈ 12 oz (410), No. 4 ≈ 15 oz (510), No. 1 ≈ 19 oz (640). The scale is a legacy of US military and sailmaking specification and is still used for luggage, footwear and heavy covers.
When you order from a mill
We weave the numbered range in 2-ply plain construction. If you spec a number, we match the weight and construction; if you spec an oz range, we map it to the nearest number.