This two volume set is a good example of typical full leather, mid 19th Century bindings where the leather has deteriorated over time - the hinges have failed, the dry leather has become powdery and not much of the original spines have survived.

The text-block(s) has remained more or less intact, but the weak points include:

• the low quality original thread used in sewing the sections ('signatures') together;

  
  

• the cost saving minimal sewing methods commonly employed,

  
  

• and the animal-based glues which have since become dry and brittle.

The first step is to disbind all of the signatures from the text-blocks.

Once separated, the signatures are ready for individual cleaning...

Each plate must be carefully detached
and cleaned of all adhesive residues...

...along with the adjoining text pages.

A strip of archival paper (in this case mulberry paper)
is then attached to the spine edge of each plate ['guarding'],
and used to permanently secure the plate to its signature.

The plate can now be, in effect, sewn in as part of the signature and is thus able to open flat with all the rest of the text pages, without putting any direct strain on the adhesive or guarding paper.

The next step is to assess each signature for any tears,
tattered edges, or signs of weakness in the fold area.

A variety of archival tissues and papers are used to correct these problems.

In the event of a complete separation at the fold,
the same 'guarding' technique, employing strips of repair
tissue or paper, is used to rejoin the leaves back to a single folded sheet.

After cleaning and repair, the restored signatures
are ready for hand sewing onto cloth tapes or cord.