Ounce Weight (oz/yd²)

Ounce weight measures the same thing as GSM in different units: ounces per square yard. It is the convention for denim and heavier wovens (a "14 oz" jean), while knits usually quote GSM. Rough conversion: 1 oz/yd² is about 34 GSM, so a 7 oz shirting is roughly 240 GSM. Knowing both lets you compare a brand that lists oz against one that lists GSM instead of taking either firm on faith. When a spec sheet quotes neither, weight is exactly the variable being hidden.