An antique brass cap is supposed to darken. A tarnished one is supposed to be cleaned. Telling those two apart is most of what you need to know about antique brass snap caps — because the usual mistake is polishing away a finish you paid extra for.
Patina and tarnish are not the same thing
Patina is uneven and it flatters the design. The recesses go dark, the high points stay bright, and the detail of the cap reads more clearly than it did when new. That is the whole idea behind an antique finish: the darkening is applied deliberately at the factory and then continues with wear.
Tarnish is even and it flattens the design. The whole cap dulls, including the raised parts, and it can take on a gray or greenish cast. It is oxidation on the surface and it will come off.
What drives it
Moisture, mostly. Humidity is the main accelerator, which is why the same snap ages faster on a coastal customer’s belt than an inland one’s, and faster on a piece stored in a bathroom or a damp workshop than one kept in a drawer. Salt from skin contributes, so cuffs and collars darken before drawer pulls do.
None of this is damage. It is the reason we stock brass, nickel and black iron separately — they age differently, and choosing the hardware is choosing how the piece will look in five years.
Cleaning antique brass snap caps without wrecking them
- Dry cloth first. A soft cloth after wear removes most of what causes tarnish before it can settle. This is ninety per cent of snap care.
- Mild soap and warm water if it needs more. Barely damp cloth, not a soaking. Work around the cap, not into the leather.
- Dry it immediately. Leaving moisture sitting in the joint between cap and leather is what causes the problem you were trying to fix.
- A trace of wax afterwards, buffed off, puts a thin barrier between the metal and the air. A neutral furniture or leather wax is fine; you want a film, not a coating.
What not to do to antique brass snap caps
- No abrasives. Steel wool, scouring pads and abrasive creams leave a field of fine scratches that then tarnish faster than the surface they replaced.
- No metal polish on an antique finish. Polish is designed to remove the darkened layer — which on an antique cap is the finish. It will come up bright and stay bright, and the detail will go flat.
- Do not soak the leather to clean the metal. Water in the leather around a snap swells it, then it dries stiff and the hole loosens.
- Keep mink oil away from black caps. It darkens black leather and black hardware unevenly and there is no going back.
Storing antique brass snap caps matters more than cleaning
Dry, ventilated, not in a sealed plastic bag. A bag traps whatever humidity was in the air when you closed it and holds it against the metal. A cloth bag or an open shelf is better. If you keep spare snaps loose in a tin, throw a silica sachet in with them.
While you are there, check the leather
Every few months, when you are wiping the caps down, press round the base of each snap. If the leather has gone soft or the snap turns, deal with it then rather than after it has pulled through. That five-second check is worth more than any amount of polishing. If a snap has already started letting go, why your snap will not stay closed covers the three causes, and replacement caps are in our decorative snaps range. For background on the metal itself, see the brass entry on Wikipedia.
