Because raw denim is unwashed, the indigo is at its deepest and the fabric is at its stiffest on day one. Enthusiasts wear it without washing for months so the fades form exactly where they sit, crease, and move — creating a personalised pattern of whiskers and honeycombs.
Raw denim is often, but not always, also selvedge. The terms describe different things: raw is about finishing (unwashed), selvedge is about how the fabric is woven.