Embroidery
Cap frame
A cap frame is a curved hoop and frame system that clamps a hat's front panel flat so a machine can stitch directly onto its curved surface.
A cap frame is a curved attachment that replaces the flat embroidery hoop when stitching directly onto a finished hat. It clamps the front panel of a 5-panel or 6-panel cap over a curved cap frame board matched to the crown's shape, then locks onto a cap driver on machines like a Tajima or Barudan. The usable stitch field on a standard structured cap frame runs about 2.25 inches tall by roughly 4.5 to 5 inches wide.
That stitch field is the real reason cap-front logos max out around 2 inches tall, not a style choice. We've turned down 4-inch-wide logos sized for a polo more times than we can count, because the needle would strike the bill or the frame's edge before the design finished. On a Flexfit structured 6-panel or a Yupoong trucker front panel, anything wider than the frame simply won't clear, and the design has to be redrawn to the actual field, not scaled down from a shirt logo.
Digitizers compensate for the tight curvature with extra push-and-pull adjustment so straight lines don't bow once the fabric relaxes off the frame, and foam trucker fronts use a different curvature radius than structured 6-panel caps. When a logo genuinely needs more room, moving it to the flatter back panel or side, or converting it to a sewn-on patch, solves what the frame's field can't.
Buyers regularly submit the same file used for a 4-inch chest logo and expect it to fit the cap front unchanged. The cap frame's field is fixed by the hardware, not the order, so any design headed for a cap front needs its own simplified, size-appropriate digitizing pass from the start.