Envelope flap repairs

11 November, 2021

As part of the preparation for rotations in the permanent exhibition galleries starting in November 2021 and the upcoming exhibition “Meeting in Isfahan”, opening 4th February 2022, I worked on two Islamic bindings with damaged envelope flaps. In both cases, the damage to the flap structure was substantial and prevented the binding from functioning safely and as intended.  

The two bindings were different in size and weight, so the conservation requirements were different for both, although the damage was located in the same area of the bindings. 

CBL Ar 3162 is a 17th century North African manuscript (Three texts on Hadith traditions, by al-Sakhawi and al-Biqa`i). It measures 297 x 220 x 65 mm and is rather heavy due to the weight of the paper textblock. 

The damage to the envelope flap was located at the tail end of the foredge piece, where poor handling and gravity had led the leather and pasteboard to be damaged. The significant loss of material from the foredge piece was associated with delamination of the pasteboard and large breaks in the leather joints.  

In order to stabilise the structure, I rebuilt the foredge piece where it was damaged, using layers of Japanese paper adhered with wheat starch paste. I inserted new Japanese paper between the delaminating pasteboard, and built-up the paper layers at the edges to achieve an even thickness.

CBL Ar 3162, the foredge piece is rebuilt using layers of Japanese paper and trimmed to size.

Part of the leather on both sides of the foredge flap was missing. With the board reconstructed, I could cover it and support the broken joints at the same time. I used a 31gms Sekishu paper which I toned with acrylic paint to obtain the desired shade of brown. I used a combination of wheat starch paste and Lascaux 498 HV adhesives to adhere the toned paper underneath the leather, and to form a new stable foredge flap. SC6000 was applied to the paper to create a sheen, similar to leather. 

CBL Ar 3162, after conservation images of the foredge piece repaired with dyed Japanese paper.

CBL Per 251 is a 16th century Persian manuscript (Yusuf and Zulaykhā, by Jāmī) bound in a delicate red leather-edged çaharkuşe Ottoman binding (common from the 16th century onward) . The sides are covered with a beautiful green moiré or watered silk and it measures 226 x 144 mm

CBL Per 251, before conservation images of the broken envelope flap.

The binding is light and the leather at the foredge flap is very thinly paired. The damage to the envelope flap was probably the result of pulling on the flap and tearing it completely from the rest of the binding. The detached flap had been previously “repaired” using pressure sensitive tape to secure it to the binding.  

In this case, the first step of the treatment was to remove the tape from the leather and the paper doublures. I used a metal spatula which allowed me to lift the dried-out tape carrier and the adhesive residue was scrapped off lightly as necessary.  

CBL Per 251, (left) pressure sensitive carrier lifted; (middle) leather lifted at the break; (right) Japanese paper inserted to create a bridge.

This step revealed that there was very little loss of leather between the flap and the lower binding board, and I was able to lift the leather at each side of the break to allow a Japanese paper bridge to be inserted all along and discretely re-attach the envelope flap to the binding. I dyed the paper with acrylic to the tone of the leather to minimise visual disruption after assembly and used Lascaux 498 HV to avoid darkening of the leather from moisture. 

CBL Per 251, after conservation images of the foredge flap reattached.

Books are mechanical objects and the envelope flaps on Islamic bindings, although not structural to the bindings, nonetheless protect the foredge of the textblocks. However, they are often mishandled or forced into positions they were never intended for. In addition, the weight and size of each book will have a bearing on the type of damage it will sustain and the level of repair needed to stabilise it. Both damaged envelope flaps presented here have suffered different problems and required different conservation approaches. Careful treatment means they can now work to protect the textblock as originally intended. 

Julia Poirier, Book & Paper Conservator

These manuscripts will go on display in the Sacred Traditions gallery in November 2021 and “Meeting in Isfahan” in February 2022. Keep an eye on our Instagram page to see more! 

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