Metal fasteners such as staples are a common cause of damage in booklets and pamphlets. Over time, these materials can rust, discolor surrounding paper, and weaken the fold of a signature, eventually leading to tears or complete failure at the spine. Mending and reinforcing damaged signatures is an effective conservation approach that stabilizes weakened areas and prepares the booklet for rebinding, extending its usable life while preserving the original paper structure.
Materials Needed
Kozo or mulberry paper (Pre-scored hinging paper may also be used for consistency)
Brush for applying paste
Interleaving material (such as blotter paper or silicone release paper)
Wet brush or Sakura KOI Water Brush Pen
Cutting tool or scissors (for trimming excess paper)
Preparing the Signatures
Begin by carefully removing the existing binding, taking care not to further stress the paper. Once the signatures are free, open each one fully and lay it flat. Place interleaving material over the fold and gently warm it with a tacking iron. This step relaxes the paper fibers, reduces distortions, and helps flatten the crease, creating an even surface for repair.
Preparing the Kozo Reinforcement Strips
Tear narrow strips of kozo or mulberry paper to reinforce the fold. Each strip should span the full length of the folio fold and measure approximately ¼ inch in width. To control the tear, lightly dampen the paper along a crease using a wet brush or a Sakura KOI Water Brush Pen before tearing.
Tearing the paper—rather than cutting it—creates a soft, frayed edge that feathers into the original sheet. This gradual transition allows the fibers of the repair paper to integrate more naturally with the original paper, resulting in a stronger, more flexible repair. Frayed edges also reduce the risk of creating a hard line that could concentrate stress during repeated opening and closing. For added efficiency and uniformity, pre-scored papers such as hinging paper can be used, which tear cleanly along the score while retaining these beneficial feathered edges.
Applying the Repair
Saturate each kozo strip evenly with wheat paste using a brush, ensuring full coverage without excess adhesive. Using a microspatula or tweezers, carefully lift the pasted strip and place it centered along the flattened folio fold. The strip should bridge any holes, tears, or weakened areas left behind by the original binding materials.
Once positioned, lightly burnish the strip with a folder to ensure good contact and adhesion. To accelerate drying and help set the repair, place interleaving material over the mended area and apply gentle heat with a tacking iron, using minimal pressure.
Finishing the Signature
After the repair has fully dried, trim any excess kozo extending beyond the fold. The signature can then be carefully refolded. The reinforced fold will be stronger, more flexible, and better able to withstand rebinding and handling—helping preserve the booklet while respecting the original paper’s character and structure.
