Sheet Smarts by Jeffreywood

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									On Paper
          B Y CO N S TA N C E J . S I D L E S




                                                                                      You can tell grain direction in two
                                                                                   ways. First, look at the dimensions
                                                                                   of the paper as stated by the manu-
                                                                                   facturer. The grain direction is al-
                                                                                   ways given last. So a sheet that mea-
                                                                                   sures / by  has the grain running
                                                                                   parallel to the -inch side. Another
                                                                                   way to determine grain direction is
Sheet Smarts                                                                       to curve the sheet over slightly, as
                                                                                   though you were going to fold it.
A designer asked me to trouble-              While the designer’s book was in-     First curve the sheet the long way,
shoot a book she and her partner          arguably wavy, it wasn’t misregis-       and then curve it the short way.
had recently produced. The job was        tered or creased. So I suspected an-     When you press your hand against
a -page children’s picture book         other culprit—not rain, but grain.       the curve of the paper, you will no-
with beautiful illustrations printed         Let me explain. If you’ve ever seen   tice more resistance when the curve
on very fine paper. “So what’s the         paper manufactured, you know that        is against the grain.
problem?” I asked.                        a slurry of wet pulp (called furnish)       Whenever you use paper that will
   “Look at it,” the designer cried,      is poured over a vibrating screen of     be bound or folded, you should pay
flinging it onto the table. Instead of     fine mesh, which moves forward            attention to paper grain. If you want
lying flat, the pages rippled in roller-   continuously like a conveyor belt.       paper to lie flat after it’s bound, then
coaster waves of buckled paper.           The wet furnish spreads out into a       you’ve got to use paper with the
There was no denying that the book        thin layer on the screen. Excess wa-     grain parallel to the binding. Paper
would appeal to children, though          ter drips out of the furnish as the      bound with the grain perpendicular
not for reading. Any child worth her      conveyor belt moves forward. When        to the binding will curl and wave.
salt would immediately see that the       the water drips out of the furnish       Similarly, paper folded with the
best way to use the book was to           and the pulp starts to dry, the paper    grain folds more cleanly and easily;
drive her toy Ferrari over the hills      fibers begin to align themselves par-     it also tears more easily along the
and dales. Vroom, vroom.                  allel to the direction of the belt.      fold. So if you want a strong fold, you
   “I take it this book isn’t supposed    When the paper is completely dry, it     should use paper that folds against
to be interactive,” I said, but the de-   thus has a grain.                        the grain.
signer was too upset to smile.               After the newly formed paper has         If the lie-down characteristics of
   “I think the printer left these        been dried and polished, it is rolled    binding conflict with the strength
books out in the rain,” she said.         into gigantic logs. These logs are       demands of folding, you have to de-
   Her suspicion isn’t as ditzy as it     then cut into smaller rolls, which       cide whether folding strength is
sounds. Although rain was unlikely,       become the “webs” on a web press.        more important than flatness.
it is true that sheet-fed paper can       To make sheet-fed paper, the rolls          In the case of the children’s book,
sometimes buckle if it isn’t allowed      are cut into individual sheets. Paper    the folded binding was very strong,
to come into equilibrium with the         mills can cut the rolls into many        since it went against the grain. But
ambient humidity and temperature          different sheet sizes. Depending on       the pages would never lie flat. When
of the pressroom. According to the        how the blades are set, paper can be     the printer selected the paper for
Graphic Arts Technical Foundation,        cut so the grain runs parallel to the    this job, strength was more impor-
paper can require as much as four         long side of the sheet, or perpen-       tant than flatness in his judgment,
days to acclimate fully. Sheets that      dicular to it. Sheets with the grain     because he knew that children are
have not been conditioned properly        parallel to the long side are called     hard on book bindings, especially
will show wavy edges, and the press       grain-long; sheets with the grain        ones that are saddle-stitched. Un-
will produce creases and misregis-        perpendicular to the long side are       fortunately, the designer thought
ters when it prints on such paper.        called grain-short.                      flatness was more important.
                                                                                      Neither one consulted the other,
                                                                                   and that was the real problem. x

                                                                                   Constance J. Sidles is a production
                                                                                   consultant and writer in Seattle. Her
                                                                                   column “On Paper” appears in every
                                                                                   issue of Adobe Magazine.


                                                                             Adobe Magazine | Autumn 1997              23

								
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