Q: Which zipper suits a quarter-zip running tee?
A quarter-zip running tee uses a size 3 lightweight nylon coil with a closed-end bottom stop at chest height and a semi-auto lock slider. Coil is the right structure because the knit is thin, the zip is short and the garment is washed constantly; a metal zip of the same length would drag the neckline out of shape and add a cold, hard edge at the throat. Face the zip with a strip of self fabric so the coil does not pull the jersey, and finish the top with a chin guard.
- Size 3 coil, closed-end, roughly 20 to 25 cm long.
- Semi-auto lock slider with a small, soft pull.
- Self-fabric facing behind the tape on both sides.
The usual mistake is specifying a size 5 or a metal zip because it feels stronger. On a 150 gsm knit that extra weight and stiffness puckers the placket and the top stop scratches the wearer's throat. The second pitfall is a plain slider without a lock, which lets the zip drift down during a run and leaves the collar flapping open.