I was talking to a colleague recently who was convinced that board slotting, because it removes a small amount of original material from the interior of the board, was a treatment they would not perform. They insisted that the removal of original material was never acceptable.  The primary issue– when is the removal of original material ever  justified– is  important and worthy of discussion, especially when balanced against other treatments that may obscure information about a book’s construction and its aesthetics.

Obviously, no conservator condones the removal of original material.  However, when the amount removed is quite small, and it is from an interior area, I feel it has to be balanced against the types of information that can be obscured or changed during the course of a treatment that does not remove original material.

Specifically, I am thinking about the joint area of the book board.  This is a critical area of a book structure, and both the pastedowns and covering material contain and extraordinary amount of information about how the endsheets were put down, bumps from spine linings extending onto the boards, lacing patterns, and sometimes even strike-through from brush marks.  Traditional methods of board attachment often obscure, if not obliterate this type of information.  And any suspected alteration often raises questions for future historians.

Since the majority of prime candidates for board slotting tend to be 19th century books– a time period when the introduction of machinery and other productions oriented techniques– the speed and accuracy in which the binders worked, in a production setting, are important aspects of these books.  And for books that posses high aesthetic values, slotting certainly preserves the original appearance better than most (all?) other board attachment treatments.

Thoughts, anyone?


More on Syringes

May 26, 2010

I noticed that McMaster-Carr sells syringes and needles in the United States. They are currently  available in type 304 stainless steel. Gauge 25, .020″ O.D. fits a 1/64″ blade quite well, $13.97 for 50.  The 21 Gauge, .032″  O.D. fits the thicker 1/32″ blade, also $13.97 for 50.  Both are an easy to handle 1/2″ length.

As Victoria previously mentioned, there are advantage to flexible plastic needles as well.  The thinnest PTFE needle they sell is 22 Gauge, .040″ O.D., $19.43 for 10. They also have a Polypropylene needles, 25 Gauge with a .029″ O.D. for $2.23 each.

WARNING: Their catalog contains over 480,000 products and is highly addictive.


Daubeny Project: Light Relief

November 19, 2009

The last few weeks has seen me concentrating on the big questions of light and consolidation.

The Daubeny Library both benefits and suffers from being in its original laboratory setting. The context is wonderful and really adds to the uniqueness of the collection, but the light exposure it suffers from several 3 metre+ high windows which face the book presses is less great. I have been logging light levels over a number of months, as well as setting up a long term light test using samples of the dyed textile used for slotting. Light levels have become somewhat of an obsession due to the work I did on the reactive dyes, as traditionally, and somewhat unfairly, they have always had a reputation of being less light fast than direct dyes. At Daubeny, the UV light levels are encouraging but the visible light levels are slightly too high. It is a difficult space to regulate in light terms as it is used both as a library and a lecture room. Consequently I have been encouraging users to lower the blinds in the room after use, but this has had a variable degree of success. However, any lowering of light levels is a big improvement on the relatively uncontrolled exposure the collection has experienced up until the recent refurbishment of the laboratory.

Consolidation in progress. Image reproduced with the kind permission of the President and Fellows of Magdalen College, Oxford.

The chemically degraded nature of the majority of the leather covering the Daubeny books has also been a challenge. Early tests with the traditional consolidant mixture of klucel g in IMS showed considerable and unacceptable darkening of the leather, and a coarsening of the leather surface. Having done some research into the water content of common solvents, I settled on isopropanol as the solvent of choice. Unlike IMS, with a water content of up to 1%, isopropanol has a water content of less than 1%, and as such seemed a better bet not to darken the leather. I made a 2% solution in isopropanol by gradually adding the solvent to the klucel g, stirring all the time, and leaving it to fully dissolve overnight. This resulted in a very smooth, gelatinous liquid which when applied with a brush caused neither darkening nor streaks across the leather surface.

Victoria (Stevens)

After a long run in due to pressures of other work, the slotting project at the Daubeny Library, Magdalen College, Oxford, is now underway.  A preliminary selection survey showed that the books were mostly of a similar level of deterioration, giving a wide choice of suitable material, and thankfully of a broadly similar colour.  This will mean that time spent dyeing will be reduced and so more books can be repaired in the time available.

Charles Daubeny, under copyright of and reproduced by kind permission of the President and Fellows of Magdalen College, Oxford

I have selected in particular a very large folio volume to work on, as up until now I have only ever slotted small octavo sized volumes with relatively thin boards.  It will be interesting to see how the slotting process differs on a large book.  Slotting this book is further complicated by the method in which it was originally bound.  The text block is made up of single sheets whip stitched or over stitched together in a very impressive display of chunky sewing.  This may create problems when attempting to attach the first slotted lining by sewing, which will definitely be required given the size of the book.

The next area to look at is dyeing the aerocotton.  I have decided to go down the Procion MX route, and any advice and help that anyone can provide on this dyeing method would be very gratefully received.

Victoria Stevens

Earlier this month, the Oxford Conservation Consortium trialled a new sequence of procedures for slotting.  This study day was intended to iron out potential problems relating to common aspects of damage within a range of book structures.   One of our main areas of focus was on how to solve aesthetic issues relating to slotting, and in particular how to accommodate large back corners and reinstate headcaps on slotted books.   As part of this we compared the finish given by paper backed toned aerolionen and aerocotton as well as toned paper backed by undyed aerolinen and aerocotton.  As the number of books we were working on was small we used surface applied diluted acrylics for toning.

It was initially also intended as a time study to be used to project per volume times and so costs, particularly as the Daubeny Library slotting project has been scheduled in to commence in April this year.  However, solving the more practical issues and discussion of working procedures took precedence and another day is scheduled to measure the time taken for an individual item.  I hope to post the outcome of this in due course.

We worked on several books with various problems including regular hollow backed books, books with missing spines, a tight back with slightly warped boards, a book with a partially missing spine and a hollow backed book where the boards and spine had become detached but the joints were not split.

Several interesting developments came as a result of the day.  It was shown that a spine stiffener was essential where the whole or part of the spine was missing.  On creating a new headcap, it was our initial intention to shape and turn in the headcap once the boards were attached.  However, a better result was achieved by turning the headcap in before the toned material was attached to the book or slotted and by putting the turn in into the slot.  Either method has a bearing on the extent of the 1st lining on the backs of the sections to prevent the cloth from being doubled up in the turn in area.  The appearance of the headcap area was improved by rolling in a thin piece of cord with the turn in.  It was also necessary to angle the flange at the head and tail by removing a v shaped piece of material from the turn in to prevent the material being visible above the edge of the board.

Our large backcorner problem was solved by hand splitting the board at the extreme head and tail after the main slot was cut and shaping the new covering material into a “p” shape so that it was firmly attached at the head and tail of the joint.

My colleague, Katerina Powell, worked on the hollow backed book with  joints largely intact.  The boards and spine had come off as one unit, the hollow having failed, and the cover was effectively now a case.  Given the relatively strong condition of the joints and the frequency with which this type of damage is seen we decided to attempt to slot the boards without detaching the spine.  This was very successful, and the joints withstood the considerable flexing and pressure required to allow the board to be effectively slotted.  The attachment procedure was obviously made more tricky as the new covering material to be slotted had to be bent back on itself and pushed into the slot at the same time – not easy when you’re dealing with a flange only a few millimetres wide!  If the original leather/cloth of the joint is robust enough and the original appearance of the book is a high priority it would justify the extra time spent on this procedure.

The different results of toned paper and cloth were also interesting.  The aerocotton in particular had a distinct clumped, fibrous texture which was accentuated by the toning process.  This may have been reduced by dyeing the cloth in a bath or by pressing between melinex after toning, which has given us good results in the past.  The paper gave a good even result and the texture and surface finish may be further inproved by an application of SC6000.

Victoria Stevens

We have been experiencing problems with the syringe tips for applying adhesive into the slot.  Standard metal blunt tipped syringe needles are prone to clogging and frequently the adhesive is difficult to apply in an even and controlled way.  They can also be difficult to clean.

An alternative is the clear tapered syringe tips available from Preservation Equipment Limited, UK.  These tips are made from flexible translucent plastic with a diameter of 0.041mm.  This will allow a more even flow of adhesive, whilst the flexibility of the tip enables smoother and more accurate application.  The flexibility and translucency of the tips also makes cleaning easier and more effective.  They are sold in packs of 10, catalogue reference is 870-1055  from www.preservationequipment.com.  Any feedback would be welcome.

Victoria Stevens

slotter dust cover

November 21, 2008

I tend to batch items to be slotted, and as a consequence the slotter often sits unused for a while.  I made the dust cover pictured below out of binders board and covered it with cloth.  It is is simple step shape that covers the clamping bar.  This way it is not necessary to clean the carriage each time the machine is used.


Briefly, to minimize the joint gap that sometimes occurs with board slotting repairs, cover the area with solvent-set tissue after reattaching the board, as described in the BPG article, annual 22, (2003) by Priscilla Anderson and Alan Puglia, This technique can be used alone for very small books with detached boards or for larger books with cracking, but mostly intact joints. Solvent-set tissue is also good reinforcement material for head caps. When used with board-slotting, solvent-set tissue can cover the repair to leave the joint area flush.  I follow the instructions in the article closely, except for the visual refinement of dye toning the tissue. 

Instead of using thinned acrylic paint, which forms a relatively thick film on the surface of the tissue and does not allow for tearing without exposing unpigmented fibers, I now use dye.  I started using Sellaset leather dye from the Leather Conservation Center; http://leatherconservation.com/sellasetdyes.html  for the initial toning of the tissue. It penetrates the fibers better and allows for greater flexibility of the tissue.   Also, the translucent quality of the died tissue allows for the original leather grain and color to be seen, making the repair more harmonious.  I have since discovered the Levacell direct dyestuffs which would likely be more appropriate for paper.  It has a similar fixing agent like the Sellaset dye. It is important in both cases to fix the dye properly as described in the manufacturer’s instructions. More information on Levacell dye can be found at: http://www.kemira.com/en/solutionsproducts/Pages/levacell.aspx 

The dye is applied by pulling a full sheet of Japanese tissue on Mylar through a bath of dye.  I usually start with a dark brown and slowly dilute the bath or change the color slightly to lighter tones in order to stock a range of shades. You can also make colors, depending on the collection; usually reds, blues, and greens. Recently, I heard about a Plexiglas V-shaped trough that I’m told can be purchased overseas. I currently use photograph developing trays, but the trough would require less dye for each use. 

After the solvent-set repair tissue has been applied to the book, it usually requires a final toning to more closely match the shade of the book. There I find that dried paper extract as described in the article Toning with ‘paper extract’ by Piers Townshend in The Journal of the Institute of Paper Conservation, volume 26, (2002) works in most cases. The paper extract saves time by not having to mix colors and dulls the intensity of the dye to more closely approximate the color of old leather.  After the final tint, continue to follow the instruction for application of the solvent-set tissue by applying a coat of red rot cocktail or straight SC6000 to consolidate the fibers of the repair tissue, darken the repair slightly, and add a small amount of sheen to blend with the leather.

Laura O’Brien Miller


September 30, 2008

I recently purchased two items that make the slotting experience easier and more pleasant- optisight magnifier and the Shure SE110 noise isolating earphones.  The Optisight visor is much lighter and more comfortable than the usual Optivisor, and it comes with three diopters- a 1.75x that has a viewing distance of 14″, a 2x (10″) and a 2.5x (8″).  The make aligning the blade position with the board much easier.  I use them for many other conservation tasks as well, and they are fairly inexpensive.  But then again, I’m over 40.

Most slotting machines use a vacuum cleaner to remove dust, and most vacuum’s tend to be fairly loud.  It might be difficult to get your institution to provide these, but the Shure SE110 earbuds, with the foam inserts, significantly reduce annoyance, and well as being very good quality headphones.  I often wait to slot until I have a batch of boards, and not having that annoying whine in my ears for a couple of hours made these well worth the expense.  Since they block out a fair amount of outside noise, you can listen to your ipod at lower sound levels, which preserves your hearing, at least that’s how I justified their expense.