Structures for Board Slotting


Many think that board slotting is simply an easy way to insert a hinge into a detached board.  While this is true, I have expanded on Clarkson’s original structure to adapt it to various types of books and book structures, with applications for circulating to rare collections.  Of course, every book has unique problems and these are just some general approaches.  Below are diagrams and an overview of six structures, but I’m sure there are many yet to be devised.  I’m always excited to hear from all the board slotters out there about the structures they have developed to deal with the specific needs of their collections.  Angela Andres, of New York University, has added the latest one, No. VI.





-The fastest and most economical method of board slotting

-Mainly suitable for circulating collections and book repair

-Requires minimal training to execute


-Not suitable for items requiring a high degree of aesthetic integration

-Use of PVA raises questions about long-term durability

-Use of a made hollow relies more on adhesive strength than other hollow constructions (not pictured)

-The slot loses some of the endsheet on the inner board edge


-Deteriorated 19th. C. leather books with hollows that need to be used


-Place the textblock on top of the board when adhering to the spine, you can see the three squares for accurate placement

-On larger or thicker books, using both the cloth hinges the full thickness of the spine might be necessary

-Endsheet edges can be covered with toned tissue or inpainted after boards are attached for aesthetic reasons





-Very neat and strong, just one layer of cloth on the spine

-Mechanical reinforcement of the cloth adds strength

-Lifting the endsheet on the spine edge of the board makes it easier to align in the machine

-Lifting the endsheet on the spine edge results in minimal loss


-As Clarkson says, it is “fiddly” to align the book board with the textblock and fully insert  the hinge at the same time

-On somewhat brittle 19th C. books, I doubt the sewing actually contributes much strength

-Boards must dry separately upon inserting into the slot

-Takes about longer than the basic method


-Clarkson originally developed this to deal with decorated, extensively tooled bindings, with leather joints or doublures

-Books that need a more aesthetic treatment


-Hinge must be adequately stiffened to insert into the slot

-Putting the adhesive into the slot first, rather than onto the hinge makes insertion easier





-Using two layers of cloth creates perhaps the strongest type of hollow

-Less buildup of new cloth on the spine than a traditional cloth reback, so when the original spine is replaced there is less new material showing

-One layer of cloth on the spine ends creates a more natural flexibility

-There is no lifting of the cloth on the boards, eliminating the possibility of distorting an embossed grain pattern on due to moisture and pressure

-The joint is usually very easy to lift


-If the endsheets are brittle, since they are not supported by board at the hinge area, sometimes lifting/ separating  is difficult. Also difficult to keep out of the way when slotting

-Ends of the spine can look a little unfinished, since the new cloth is only one layer, not turned in


-Any Publishers case binding that has fragile cloth or endsheets, embossed cloth that could prove problematic to lift and readhere without flattening the grain pattern


-Cloth can be roughly toned before inserting into the slot, then locally toned to replicate the fading that often occurs on the spine

-The folded cloth can be inserted into one board, then the inner cloth adhered to the spine, then both layers glued together to insert into the opposite board, like the Clarkson method

-If toned with acrylics, two layers glued together seem to create enough stiffness to insert without additional backing with tissue

-The slot thickness must be thicker to accommodate the two layers of cloth (.032 or .051”)





-With  thin, deteriorating spine leather, this can add flexibility to the textblock, while preventing the original spine from flexing

-Spine is easily reversible

-Good for large, heavy books


-Molded paper spine and two layers of cloth adds additional thickness so there may be extra space around the original spine in small books. This can be infilled or toned if desired

-Radically changes the entire original structure


-Any leather book with raised cords, sound sewing and a fragile leather on the spine

-Books with a split spine.  The paper Mache spine liner can provide quite a bit of strength

-Thick and oversize books


-The sewing structure must be strong enough to withstand more flexibility

-Cover the lifted spine with thin cling wrap, build 2-3 layers with wheat starch of very thin western paper or stiff Japanese tissue, tie up in a press to mold exact sewing support pattern

-Let dry tied up overnight





-Eliminates the need to lift an entire thin, firmly attached spine

-Slotting only the head and tail panels adds strength at critical areas

-Suitable for books with raised bands and smooth spines

– Vellum can be used instead of linen. Given its inherent rigidity, is very easy to insert into the slots and adds less thickness to the spine.


-Large or heavy books may not be adequately supported

-If using Vellum instead of linen, the thinnest (.010”) blade is most often used.  This blade, because of its thinness is difficult to use.  It can easily deflect


-Octavo or smaller books that have a thin, firmly attached tight back spine


-Vellum, instead of linen, often adds a more natural swing to the boards, and helps to keep the spine from flexing and creasing or splitting the unlifted spine areas due to its rigidity. 



There is an useful article in “The Bonefolder, Vol. 4, No. 2″ about a new boardslotting structure developed by Angela Andres from  NYU, titled “A New Variation on Board Slotting: Case Binding Meets in-boards Binding”.


“Board slotting creates a very strong and aesthetically integrated  board reattachment for many books; however, books with  significant losses in their spine material require additional structural compensation. An adapted board slotting technique that addresses this specific concern is discussed.” 



2 Replies to “Structures for Board Slotting”

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