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Rounding and Backing with PVA

           See The Exhibition Online, And Order Your Catalog.

A hot stamping student visiting from DC said "I make flat back books because
rounding and backing is too difficult." This has been a common litany in recent
years, so I thought the book_arts-l members might be interested in why she found
it so hard and why it's really easy.

First, a short rant. I love round back books. Flat backs may be fine for
sketchbooks (where you want to draw across the fold), and some thin volumes, but
the feel of a round back in the hand is much more satisfying. The round back
also helps keep the spine from going concave with use.

This student sewed her books on raised cords. If you go to the trouble to do
that, then you might as well go all the way and have a round back laced-in-cord
binding. An example is at:

The subject came up because I was showing her how to make jigs for aligning
spine stamping on round back cases and flat back cases. If folks on this list
request it I can post that info as well. A leather round-back case binding with
gold stamped spine and covers is at

The problem with the way many people do rounding and backing is that they glue
up the spine with a solid coat of PVA before they start. That makes it very
difficult to do the backing. It's a carryover from the days when hot horsehide
glue (or a mixture of protein glues) was used for the spine of books. Animal
glue allows a very important step that you can't do with PVA.

When I first learned rounding and backing, we glued up the spine flat (with hot
glue) and let it cool until it was no longer tacky. This is done with the book
lying flat on a 3/4" board, with the spine extending about 2 mm beyond the edge
of the board, setting the spine square (using a carpenter's square or triangle)
and being sure all the sections are properly aligned. For an edition, this can
be done in stacks, with binders board between the books. A board and brick are
placed on top of the book (or stack) while gluing up and drying. Then we rounded
the book, holding it flat on the table with the foredge toward us, with the
thumb pressing the middle pages and the fingers pulling the endpapers, and
tapping the book at the spine edge of the endpapers with a backing hammer.

When the book was rounded to the right shape, it was put in the backing press,
or between tapered backing boards, with the thickness of the binders board + 1
thickness of the turn-in material (cloth, leather, etc.) extending from the
board. The press was tightened (very tight--with the old Hickock lying press I
used the steel tightening bar). The spine was coated with flour paste and
allowed to sit until the glue softened, and any excess glue was scraped off the
spine. Then the book was backed.  It was easy to back the book, because the only
glue left was between the sections and soft, and the paper was still damp from
the flour paste, so even hard paper moved easily.

These days I see people trying to back books with a hard, dry coat of PVA on the
spine. The spine is almost immovable. I discovered this problem when I first
switched from animal glues to PVA.

The solution is easy. The function of the first gluing, when the book is flat,
is to hold the sections together so they don't slip when putting the book into
the press, and to hold the round shape.  With PVA all you need is a few very
thin stripes of PVA between the tapes or cords, and on either side of the
kettlestitch. Be sure to use a flexible PVA, the kind with internally bonded
copolymers (like the old Jade 403 or Elvace 1874, not the stiff Promacto A1023
that is used to glue box edges). A stripe of glue " (6 mm) wide is plenty. This
should be applied so it goes between the sections, and is wiped off the surface
of the spine before it dries. Be sure not to get any adhesive on the tapes,
cords or threads, because the sections have to be able to move along the sewing
support to form the shoulder.

This will hold the sections together very nicely, and leave a lot of flexibility
for shaping the spine. When the PVA is dry, round the book gently. You can
adjust the final shape while it is in the backing press, before tightening it
fully. When putting the book in the press it is very important to be sure there
are no "dropped" or "raised" sections, and that the shape of the spine is an
even, pleasing curve, with the same amount extending evenly above both sides of
the backing boards.

One error I have often seen students make that causes uneven shoulders on the
book is that they stand next to the press and tilt their head to see if the book
is in the press correctly.  The only way I have found to consistently get a
correct symmetrical spine is to stand at each end of the press facing head or
tail, and bend the knees, keeping one's back vertical and eyes parallel to the
floor, with one's eyes level with the spine of the book.

Once the book is in the press perfectly, tighten the jaws of the press.  The
next problem occurs when students start out by hitting the book with the backing
hammer, crushing sections and/or getting wavy sections.  This can easily be
avoided by starting the backing with your thumbs. Standing on one side of the
press, place the inside of the top joint of the thumbs at the point you want the
backing to begin, and roll the thumbs outward, pushing the sections gently, all
along the spine.  I prefer walking around the press and doing this in a motion
away from me for each side of the book, using my body weight to assist on big or
stiff volumes. But it can be done from one side, or even the ends of the press.
Whatever is most comfortable and least stressful.

Check that the shoulder is coming out the right height--not too big or small for
the boards. If there is an error, correct it before proceeding.

In a couple of minutes the shoulders can gently be eased into the right shape.
Once the shape is generally correct, the backing hammer can then be used to tap
the sections flat to the backing boards, or if a backing press is used, to the
bevelled jaws of the press. They will then be slightly more than a right angle,
but will settle back to 90 degrees when removed from the press. Some large
volumes and those with stiff paper or thick sections may require more hammer
work using the traditional tangential motion.

When satisfied that the shape is correct, apply a thin coat of PVA to the entire
spine. The spine lining (crash, super, mull, or whatever you use), machine
headbands (if that's what you are using) and lining paper or hollow back can all
be applied at this point. That will set the shape of the spine permanently. If
you are going to further trim the book after backing (as with a plough), or if
you plan to sew endbands, the spine lining only can be applied.  This gives sewn
endbands a little extra strength, being sewn through the lining.  The glue and
lining help the spine hold its shape during subsequent operations.

The paper lining or tube can go on after the trimming and headbanding. That is
best done by replacing the book in the lying or backing press, being sure to use
the proper posture for verifying the correct shape of the spine.



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