Pairs to Seventeen

Now then. Sit yourself down, or stand if you'd rather — most people stand at a stone — and let me tell you what's in front of you before you touch a thing, because it will save us both a certain amount of trouble later on. That is the A. & P. Society's show catalogue, sixteen pages, made up and standing in galleys along the top of that rack there, every one of them set and corrected and ready, and the whole lot of it has got to be locked into a chase, printed, folded three times and trimmed at the head, and sitting on the folder's bench by four o'clock this afternoon so she can have it stitched and away by Friday. The pressman has already been up those stairs twice to ask how we're getting on, and I have told him twice that we are getting on very well, which we will be, once you and I have had this out.

Sixteen pages is eight leaves is one sheet, printed both sides and folded three times, and that is the whole of the arithmetic, no more of it than that. One side of the sheet is what we call the outer forme, and it carries pages one, four, five, eight, nine, twelve, thirteen and sixteen. The other side is the inner forme, and it carries the rest. Which side is which is only a question of which face of the paper is showing after the third fold — nothing more mysterious than that, whatever it may look like from where you're standing.

"Add the first to the last, the second to the next,
and every pair that meets on a fold should come to seventeen exact."

That is the whole trick of it. One backs sixteen, four backs thirteen, five backs twelve, eight backs nine — and in the inner forme the same again, two and fifteen, three and fourteen, six and eleven, seven and ten. A compositor who keeps that in his head cannot go far wrong, and a compositor who doesn't will build me a very reasonable-looking forme that folds into rubbish. I have seen it done by men who ought to have known better, and I don't say that unkindly — young Colin, who set the jumping and hunter classes for me on Tuesday and set them very neatly too, built his first forme with every page standing the right way up, which is a forme that will fold beautifully and read like nonsense from cover to cover.

Because that's the other half of it. Half the pages in that chase have to stand on their heads. Their feet meet the feet of their neighbours down the centre of the sheet — that's the fold — and the head margins of the pair sit back to back with the trim between them. A pair that's both standing upright, or both standing on their heads, will meet head to head or foot to foot instead of head to foot, and the fold goes through the wrong margin entirely. You'll feel it before you see it — the numbers stop working.

"Tighten them true and tighten them slow — never but two at a time, or below —
a forme locked fast in a hurry will bow, and a forme that bows won't come off the stone now."

Now — pick a page up. Touch it, or click it if you're working with your finger on a mouse instead of your hand on metal, and it will lift; set it down on an empty space in one of the two formes below and it will sit there; pick up a page that's already sitting somewhere and touch a second one, and the two of them will change places, which is the whole of the moving I'm going to ask of you. Every page reads backwards, face up, the way type always does — that part I can't help you with, and nor would I want to, the numbers at the foot of each one are your folio and they're honest even mirrored. Click the little turned arrow on a page once it's placed and it goes over onto its head. When you believe you've got it, pull the sheet, and we'll see what we've made.