Double Fold Bias Binder (28MM) Evolve BLE8 - Double Fold Bias Binder - 28mm (BLE8-S3) This double fold bias binder will turn fabric strips into binding and attach it to project edges all in one step. This attachment is exclusively for the Coverstitch and Evolve, and is perfect for curved edges, collars, and necklines on knit or woven fabrics.