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;  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: 

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

Biggest Board Slotted?

October 16, 2008

The blade couldn’t get to the last centimeter or so at either end so I cut them away by hand. I was pretty pleased that it fit in the platen, though!

A Bit of a Trick

October 16, 2008

Some boards are more problematic in this way than others, but cleaning the slot out in the end is really important for inserting the rebacking material evenly, and I had a few rather brittle boards I didn’t want to bang on the table to knock the sawdust out. It’s been working rather well for me, however, to disconnect the tubing that leads to the vacuum and run it along the slot before taking the book out of the platen. The hose is wider than the slot, so doing this while the board is clamped offers some surface area on either side to give better suction than holding the board in the air.

Blade Longevity

October 16, 2008

We’ve been using carbide blades at Columbia and keeping track of how many boards we slot to get an idea of the life of these things. We have a 1/64″ (which doesn’t get as much use), and a 1/32″. Jeff tells me the old blades were able to slot 10 boards before they were exhausted, but the first carbide blade we put on our machine went through 102 before I retired it so it seems like a good investment. (Less time wasted switching out & disposing of blades, too.)

I think these blades can be resharpened also, right? We haven’t looked into where to do that just yet.

Slitting blades supplier?

October 3, 2008

Jeff recently recommended using carbide slitting blades instead of the high speed steel ones originally specified.  These are manufactured in the US by Johnson Carbide (see link on blog homepage) and distributed through MacMaster-Carr.  I have tried to find a UK supplier of solid carbide blades, ideally with the same hole diameter of 1/2″ to avoid the need to modify the machine.  Does anyone have any suggestions for a UK supplier?  Victoria