Merino Wool

Merino fiber runs around 17-24 microns in diameter, roughly a third the thickness of standard wool, which is what keeps it from itching the way coarser wool does against skin. The fiber's scaled surface naturally wicks moisture vapor and traps air for insulation, and its keratin structure binds odor-causing bacteria instead of just masking them, so merino base layers can go multiple wears between washes without smelling.

It's the fiber behind premium outdoor and athleisure blanks that charge a real premium over polyester performance tees — think merino hiking layers and no-stink travel shirts. We warn every client bringing us a merino order that heat-applied decoration is a bigger risk here than on cotton or poly: wool scorches and felts at temperatures well below what a standard heat press runs for vinyl or transfers.

Screen printing with a water-based or discharge-style ink at a lower cure temperature is the safer route on merino; anything requiring a long, hot press dwell risks felting the fibers or leaving a permanent shine. Embroidery is generally the safest heavy-decoration option since it skips heat entirely.

Buyers frequently spec merino the way they'd spec a cotton-poly blend and expect standard heat-transfer pricing and process. Merino's heat sensitivity changes the decoration method and cost before a single design element gets discussed, and skipping that conversation is how runs get scorched.