Wet it. Wetter than that — keep the tray running over it every minute you're working it, and don't lift it out to look at it, either. A shell that dries out throws dust off the tube, and the dust is the thing that puts cutters in the ward with their chests ruined. That's the first reason. The second reason is money: dry nacre chips at the rim instead of cutting clean, and a chipped blank grades out at the gauge table and pays you nothing. So the water is worth two things at once and it costs you nothing to keep it running.
Now look at the shell before you touch it. Everybody wants to start cutting. Don't. The thick meat sits toward the hinge, always, and it thins out all the way to the lip, and the lip will not hold a blank no matter how good it looks lying there flat and pretty in the water. I've watched fellows crowd the lip trying to look clever — get one more thirty out of a shell, tell it at dinner — and every one of those blanks comes back thin and cracked and worth exactly nothing. I don't crowd the lip. I look at a man who crowds the lip the way you'd look at a man betting on rain.
Big first. Take your thirties while the whole shell's still open to you, put them in the fat of it, and then let the eighteens crawl into whatever's left over. Go the other way round and you'll have a shell that looks awful busy and pays like an empty coat pocket, because six little cuts scattered anyhow will lock a thirty out of a place a thirty would have fit.
Arithmetic, since you'll want it: a line is a fortieth of an inch. Thirty line is thirty-fortieths, three-quarters of an inch across. Do that once and never again. Thirty pays eleven cents the gross, eighteen pays six. That's not double, is it — and a thirty eats near three times the shell an eighteen does. So one thirty and two eighteens beats two thirties every time on a shell shaped like that one. Do the arithmetic before the cut and not after.
Kerf. The tube takes a bite about a thirty-second wide, and it takes that bite off both sides of the line. Set your second cut right up against the first cut's wall and the tube will take the first one's edge away with it, and now you've paid for one blank twice and got neither. Leave a hair. A hair is cheaper than a blank.
The chalky end at the beak — skip it. I know. It's the fattest part of the whole shell and it makes you sick to leave it. It's also worn soft on the outside from lying in the river, and it comes apart in the tube and takes your nerve with it. Skip it. I've been at this bench since March and I've never once been sorry I skipped it.
Thirty-six's on the card because somebody in a factory someplace wants coat buttons. You can take one. It's fourteen cents the gross, which sounds handsome, and then you'll look down and you'll have strangled the shell and you'll be short a thirty and two eighteens and I will be at the tally window ahead of you eating my dinner.
You crack one, don't stop and look at it. There's no putting it back and there's no undo at this bench. You've got a hole with a ragged edge in it now, and the only question worth asking is what still fits around the hole. Ask that one fast — the tally's at noon.
Call the shell before you cut it. Out loud, if you like. Four thirties, three twenty-fours, six eighteens — say where they go, then go there. When I call a shell right on the first look I'm pleased with myself all morning and I don't care who knows it.