When I went to my first button club meeting, the ladies talked about shanks and backmarks and box lots, and I nodded along as if I knew. I didn't. Here's the list I wish somebody had given me.

Backmark

The name, mark or words stamped on the back of a button, usually a metal one, by the company that made it. It can tell you a great deal about when and where it was made.

Bakelite

One of the first plastics made by man, from 1907 on. Heavy, glossy, often in bright colors. The button of the 1930s and '40s.

Black glass

Glass buttons made to look like jet. There are more of them than of almost any other kind, in more shapes than you'd believe.

Box lot

A box of odds and ends sold all together at an auction. The best buttons I own came out of box lots.

Calico

A tiny china button printed with a pattern to match the calico cloth of the 1800s. Made in France.

Card, or store card

The piece of cardboard buttons were sewn on to be sold. Buttons still on their card are worth more left on it.

Casein

A plastic made from milk. Yes, milk.

Celluloid

An early plastic, older than Bakelite, often made to look like ivory, tortoise shell or pearl. Fragile with age, and it burns.

China button

A button made of porcelain. Calicoes are china buttons, and so are a great many plain white ones that look like nothing much until you know better.

Escutcheon

A separate little piece of decoration, usually metal, fastened onto the face of a button.

Jet

A hard, black, very light material from England, made by nature out of ancient wood. Victorian ladies wore it for mourning. Real jet buttons are much scarcer than black glass ones.

Lustre

A shiny metallic or rainbow finish put on glass buttons. Pretty, and easy to rub off, so be gentle.

Mother-of-pearl

The shimmery inside layer of a shell. Ocean shells for the fancy buttons, river mussel shells for the everyday ones.

Picture button

A button with a whole scene on it. Usually means the big brass buttons of the late 1800s.

Realistic

A button shaped like the thing it shows: a cherry, a puppy, a pretzel, a little teapot. Most are plastic, from the 1930s and '40s, and they make everybody smile.

Self-shank

A shank made of the same piece as the button itself, molded or carved, instead of a wire loop.

Sew-through

A button with holes going through it, two or four usually, and no shank. Most of the buttons on your shirt.

Shank

The loop on the back of a button that the thread goes through.

Tray

The board or card that buttons are mounted on for a show. When you hear button ladies talk about "my tray," that's what they mean, and they are very particular about it.

Two-piece

A metal button made of a front and a back pressed together around the edge.

Vegetable ivory

Buttons carved from the hard nut of a South American palm tree. It looks a good deal like real ivory. Popular in the late 1800s and early 1900s, especially on men's clothes.

First, a confession. In 1962, when I was new at this and very proud of myself, I poured a whole jar of buttons from an estate sale into my kitchen sink with hot water and dish soap to give them a good bath. When I fished them out, a lovely old celluloid button had warped like a potato chip, two glass buttons had lost their gold paint, and the wooden ones were ruined. I sat at the kitchen table and cried, and Bernard made me a cup of tea and said, "Well, now you know." He was right. Now I know, and now you will too.

Plain glass and china (black glass, calicoes): These are the sturdy ones. A little mild soap in lukewarm water, a soft old toothbrush, a quick rinse, and dry them right away on a towel. But if a glass button has paint, gold trim or a lustre finish, don't wet it. Just a dry soft brush.

Mother-of-pearl: Don't soak it. Shell is made in thin layers, and water can work its way in between them and make it flake. Wipe it with a barely damp cloth and dry it right away.

Brass picture buttons and uniform buttons: Do not polish them. This is the one people get wrong most. That darkening on old brass is part of its age, and collectors want it. Polish wears down the fine little lines of the picture, and a shiny scrubbed button is worth less than a dark one. A soft dry brush to get the dust out of the corners is all they need.

Bakelite: A quick wipe with a damp cloth, dry it, and buff it with a soft cloth. No soaking, no harsh cleansers.

Celluloid: No water, no heat, and above all no nail polish remover, which will melt it. Dust only. Old celluloid can break down as it ages and give off fumes that harm the buttons near it, so keep celluloid by itself, where the air can get to it, and not shut up in a tight jar.

Vegetable ivory, wood, leather and cloth-covered buttons: Keep them dry. Water makes them swell and crack. A soft brush only.

Buttons on their store cards: Leave them be. Don't take them off and don't clean them. The card is part of the button.

And never, ever: the dishwasher, bleach, scouring powder, vinegar, silver polish or a wire brush. I have heard of every one of these being tried, and I have seen the results at button club, and it is not a pretty sight.

Storing them: Shallow drawers, or sewn onto cards, out of the sunlight, somewhere not too hot and not too damp. Not loose in a jar where they rub against each other all day, the way my mother kept them. (Except Mother's. Mother's stay in the tin.)