Sanforized
A pre-shrinking treatment for cotton fabric. Sanforized denim shrinks ~1% on first wash; unsanforized shrinks 5–10%.
Sanforization is a mechanical pre-shrinking process developed in the 1920s by Sanford Cluett. The fabric is fed wet through a rubber compression roller that forces the warp threads into a tighter, pre-shrunk configuration. The result is fabric that holds its dimensions through normal washing — a "Sanforized" tag means you can wash and wear at the size shown without dramatic surprise shrinkage.
The distinction matters most for raw denim. Most modern denim is sanforized; the first wash brings 1–2% shrinkage, which is small enough that brands sell the actual finished size. But a small subset of "shrink-to-fit" denim — Levi's 501 STF, certain Japanese mills — is sold unsanforized. Out of the bag it's 1–2 sizes too long; the buyer is expected to soak or wash the jeans to shrink them down to fit.
Unsanforized denim has a small craft following: the shrinkage produces a more characterful fabric (more loom-state irregularities, more contrast in fade patterns) than the smoother sanforized version. But the sizing math is brutal — buy the wrong size and you have ruined jeans. Most readers, even committed denim wearers, are better off sticking with sanforized.
Oz (fabric weight)
Ounces per square yard — the imperial unit for fabric weight, used most often for denim, canvas, and other heavy fabrics.
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.