Not every closure is a sew-through disc. Coats, cheongsams, kidswear and bags pick specialty closures because the fabric, the culture or the factory method will not take a standard four-hole. The buyer’s job is to name the mechanism, not to send a photo titled “nice button.”
Press snaps (four-part)
A press snap (spring snap, four-part fastener) is a clutch: cap, socket with an S-spring, stud, and prong or post on the reverse. The stud clicks into the socket. It is a mechanical part, riveted or pressed through the cloth, not sewn as a disc. Plastic and resin-face versions exist for kidswear; metal is the default when nobody says otherwise. Full construction notes belong on the dedicated snap page — the point here is: if you need one-hand close on a jersey or a down jacket, you are in snap territory.
Sew-on snap buttons (two-piece sew-through snaps with a spring) still appear on light garments and on some European boards. They are not the same tool as a four-part punch snap.
Frog buttons (pankou)
Frog closures (盘扣) are fabric loops and knots, historically Chinese, still the correct closure on many qipao, tang jackets and occasion coats. They are made from bias tubes (sometimes wire-cored for shape), not from a drilled disc. Spec the tape fabric, the knot style and the stitch-down length. They do not go through a buttonholer.
Toggles, covered buttons, horn-look
Horn-look toggles are often resin castings, sometimes wood, bamboo or real horn, used on duffles and winter knits. The loop is a separate trim (leather, webbing, cord).
Covered buttons wrap a metal or plastic mould with the garment fabric (or a contrast). They match the cloth by definition. They fail when the covering fabric frays or the mould crushes.
Resin novelties — specimens, glitter, cartoon shanks — are decoration. Put them on the same small-parts and wash plan as any kids’ sew-on.
Jeans tack buttons are not this page
A tack button is a riveted denim closure. It is listed here only so a designer does not file it under “specialty sew-on.” See the jeans-button note.
Buying rule
Write open-close method + attachment + material. “Coat button” can mean a 32-ligne urea shank, a four-part snap, or a frog. Those three quotes will not match, and only one of them belongs on your factory’s punch.
Magnetic closures appear on bags and some coats; they are a magnet plus a keeper, with a different kids-safety conversation (loose magnets). Do not file them under press snaps. Covered-button moulds must match the cloth thickness; a stretch jersey cover on a rigid mould wrinkles.
If the factory cannot frog-knot or cannot punch a four-part set, change the design in sampling, not in bulk.
TrimGem will not substitute a snap for a frog to hit a price.