Oz (fabric weight)
Ounces per square yard — the imperial unit for fabric weight, used most often for denim, canvas, and other heavy fabrics.
Most denim and canvas in menswear is specified in ounces per square yard rather than GSM. The conversion is roughly 1 oz/yd² ≈ 33.9 GSM. A 14oz denim is about 475 GSM; a 21oz "raw" denim is 712 GSM and stiff enough to stand up on its own.
Lightweight denim runs 9–11 oz (305–375 GSM) — softer, more drapey, less durable. Standard 12–14 oz is the workhorse range for most everyday jeans. Heavyweight 15–17 oz starts breaking in slowly with characteristic fade patterns. Above 18 oz is hobbyist territory: months of break-in, dramatic wear marks, but uncomfortable in summer and slow to soften.
For cotton tops the metric is usually GSM; for jeans, jackets, and chore coats the number is usually oz. Both measure the same thing.
Selvedge denim
Denim woven on traditional shuttle looms, producing a clean self-finished edge that doesn't fray. Slower to make, more expensive, often higher quality.
Raw denim
Denim that has not been pre-washed or pre-faded. Starts stiff, dark, and uniform; develops fade patterns specific to the wearer over months of break-in.
Sanforized
A pre-shrinking treatment for cotton fabric. Sanforized denim shrinks ~1% on first wash; unsanforized shrinks 5–10%.