Big, fast-fashion brands have traditionally ignored the second-hand market, but it’s grown too large not to get into the game. H&M and Spanish clothing giant Zara are leading a new trend, opening portals where clients can sell and buy their used brand-specific shirts and skirts. The companies say they’re joining the circular economy, but critics call it green-washing, arguing that Big Clothing has no plans to slow down the amount of new clothes it produces.