Like a favorite pair of beat-up shoes or worn, comfy jeans, a beloved baseball cap looks beautiful to its owner -- no matter how frayed or tattered the hat gets. And while a needle and thread can patch up rips in the body of the cap, repairing a damaged brim that's lost its shape requires a different strategy. Apply constant, prolonged pressure to help mold a flattened or misshapen brim back to its proper form.
Bend the brim with your hands. Squeeze it into a tight curve and hold the position for about a minute to see if it retains an arch.
Wrap a rubber band tightly around the brim to form an arch. Leave the hat alone for one to two days until the brim forms the desired bend.
Stuff the hat, brim-side down, into a coffee mug. Make sure the brim conforms to the contour of the mug. Stuff a clean rag inside the cup to apply pressure to the brim if needed. Leave the cap in this position overnight.
Place a canned good on the interior side of the brim. Wrap a rubber band around the outside of the brim so it envelops the can and takes its shape. Allow to sit overnight.
Trim any long, dangling threads off of the frayed edges of the brim with a pair of scissors. Take care not to cut too close to the brim.
Apply craft or school glue along the edge of brim where the fraying occurred.
Rub the glue and fibers in one direction to create a smooth edge. Allow to dry overnight.
As a last resort, especially if you don't want to discard the hat, purchase a device designed to curve the brim of a cap.
Baseball caps from the 1980s or older typically contained cardboard in the brims, while today's brims consist of plastic. While the material of the brim doesn't matter so much when fixing its shape, care should be taken when washing a cardboard-brim hat. To prevent warping, spot clean cardboard-brim hats and air dry.