Right in the heart of this Soho store is a small, glassed-in factory with ten seamstresses behind whirring machines, knocking out two pairs of custom jeans a day. If you have a hard-to-fit physique (many athletes come here), it may be worth getting a pair (they cost upwards of $700 but are made from selvedge denim and so will last 7 years). For the rest of us 3x1 offers unusually well-fitting, ready-to-wear pairs (they use a stretchy denim that flatters everyone—really, it’s like the sisterhood of the traveling pants), starting at $185/pair.