The University of Florida has an even tougher standard: “A book is considered18 brittle for University of Florida’s Preservation purposes, when the paper is weak enough to fail the ‘double-fold test’ at five [double] folds or less.” (Perhaps it’s five because of Florida’s humidity; you need to do more folding to get the results you would get up north.) A library staff member who encounters what is by this extreme definition a brittle book routes it to the Brittle Books Department, with a flag in it bearing the “dft result” (“dft” means double-fold test) — from there the marked book enters the twilight realm of “planned deterioration.”19 If and when20 the book produces a double-fold test number of less than one, it is withdrawn.
This is of course utter horseshit and craziness. A leaf of a book is a semi-pliant mechanism. It was made for non-acute curves, not for origami. If you wanted to test the effective springiness of a watch spring or a Slinky, would you bend a short segment of it back and forth until it broke? If you had a tree in your yard that survived storms by bending and dipping in the wind, would you consider cutting it into firewood because one of its twigs snapped when you bent it in two? Would you check the resilience, and hence the utility, of a diving board by counting how many times you could fold it back on itself before it failed? No, you would not. In fact, a diving board that you could double-fold ten times might be an unacceptably floppy diving board.
The point is that if you bend an intentionally stiff-but-flexible item past the point of its return-memory, you will begin to break it, and that incremental breakage brings a separate set of physical processes into play, with their own plottable curves and points of final rupture. Klaus Hendriks, the paper scientist from Canada, wrote that “one cannot qualify a book page21 that can be turned over and read as being at the end of its lifespan, even if a corner breaks off after one fold. As long as no mechanical force acts upon it, it will survive a while longer. One will be able to read it and turn it over for years to come.”
CHAPTER 18. A New Test
Late one night, after the children were in bed, I began some random experimentation at the household bookshelves. My wife asked me what I was up to.
“I’m — I’m performing the fold test,” I said.
“Please stop breaking the corners off our books,” my wife said. “It can’t be doing them any good.”
Before the survey was suspended, I had found that Saintsbury’s Essays in English Literature, Thomas De Quincey’s study of Richard Bentley, Lessing’s Laocoon, and Christopher Morley’s The Haunted Bookshop flunked their fold tests. A few months later, I bought a book of essays by Edmund Gosse1 called Questions at Issue, published by Appleton in 1893. The more I read it, the more I liked it, and the more I liked it, the more I wanted to find out how it would rate in the eyes of a preservation administrator. I put my thumb to work on a lower corner of page 153, the last page of an essay called “The Limits of Realism in Fiction.” There was almost instant breakage — the corner fell away before it had completed the first leg of the double-fold cycle. If I were doing a survey of my collection, I would be forced to assign this book a dft result of 0.4 or so — a death sentence in some libraries. If I cut a strip out of page 153—which I am unlikely to do — I probably wouldn’t even be able to get it clamped and under proper tension in the MIT machine before it would break. This was the sort of book over which preservation people shake their heads and say, “It’s got one read left in it.” Or, in a sad but firm voice, “We’ve got just one chance to turn these pages, and it better be when they’re under the camera.” Untold numbers of books with fold-test results better than that of my copy of Questions at Issue have met their unmaker in windowless offices of preservation reformatting.
And yet this was clearly a usable book: I was using it, and not gently, either. I don’t cover books with plastic sleeves; I pile them on the floor around my chair, and sometimes the piles topple. Any manual procedure that would conclude that my book was “unusable” or “unserviceable” was a flawed procedure. Klaus Hendriks was right, I thought — the existing tests are inadequate. To test a toaster you toast with it, to test a circuit board you run it for a burn-in period, to test tires you drive them on a test track, to test a heart muscle you put its owner on a treadmill. Suddenly something came to me: a new test for paper.
You don’t have to be a scientist or a conservator to perform my “Turn Endurance Test,” and it’s nondestructive. The protocol is as follows. Open a book to a middle page. Lift the top of the page a little with your right forefinger. Now, when you’re ready, turn the page, as if you had just read it. Then, with your left hand, restore the page you just turned to its initial position. Turn the page, turn it back; turn the page, turn it back. Each turn cycle may be called one double turn, or DT.
I performed a full-scale Turn Endurance Test on page 153 of Gosse’s Questions at Issue, the very page that had acquitted itself so poorly in a regulation fold test. I turned the page2 once… and nothing happened. The paper did not crack, disintegrate, or compromise itself in any way. Again I turned — and the paper was sound. I turned the page ten times — then twenty, then fifty. Each time, I let it return all the way to a point of rest on the right-hand page-block, so that in lifting it for the next cycle I would duplicate all the top-edge stresses of normal use. Each round trip took me about two seconds.
After two hundred turns, I began to enjoy myself. It wasn’t tedious; I got good at it. At the beginning of each cycle, the title of Gosse’s next essay disclosed itself on the page beneath: “Is Verse in Danger?” (Gosse believes that it is.) I looked down at the lower corner I’d broken off and regretted that I’d done it, and yet if that lost corner indirectly saves a few books it will not have been creased in vain.3
After four hundred double turns I stopped. Barrow claimed that the test for fold endurance simulated the to-and-fro bending of a leaf in actual use — but that can’t be right, since my fold-failing page 153 had just flexed eight hundred times (at two bends per cycle) with no hint of damage. Its top edge, where my fingerprint ridges caught and curled it back slightly each time to initiate the turn, was unmarked. Questions at Issue was (by definition) a very brittle book, if you compared it with brand-new paper, or old rag paper, but my ten minutes of research indicated that I would be able to read it four hundred times, which was plenty. There is, then, a broad infrared spectrum of serviceable frailty below “breaks at one-half fold” that the act of folding simply cannot sense. In the early sixties, Barrow once took a reporter4 for the Richmond News Leader down to his lab:
“See,” he said, taking a yellowed book off a shelf of yellowed books. It was an old cookbook. “Printed in 1905,” he said, as page 282 came out in his fingers. We folded the paper over, then back. Two folds were all the paper could take. The page fell into two pieces, and the recipe for Chicken a la Terrapin was cut in half.