Rare atlases – a conservator’s perspective, Part 2

The ‘papermaker’s tear’
Sometimes during the handmade papermaking process a droplet of water would fall onto a newly made sheet, causing the wet pulp to thin and form a lighter spot, known as a ‘papermaker’s tear’. Cloudy formations could also happen, due to the pulp being spread unevenly (perhaps the fibre hadn’t been beaten long enough, or the pulp wasn’t sufficiently agitated in the vat).

Metal specks
You’ll often see metal specks in handmade paper. They can sink from the wire mesh into the wet pulp during production. These unsightly brown inclusions are prone to rust when exposed to damp over time, resulting in dark-brown spots surrounded by paler-brown haloes. This corrosion is typical of the degradation that can impact works on paper. Storing works on paper in a stable, dry environment is standard preventive conservation practice to ensure the best long-term preservation of objects like the ANMM’s atlases.

The printing process
To print images such as the amazing illustrations in our atlases, the printer would first reproduce a drawing by etching it onto a metal plate. Then he’d place a damp sheet of paper onto the etched metal plate and feed it into a printing press. The press’s compression and deformation of paper fibres at the edges of the plate created weak areas in the paper matrix. This weakness, plus a reader turning a page repeatedly over time could crease the paper, or worse, tear it along these lines.

Brown staining is another type of degradation caused by the offsetting and migration of oil-based printing ink (linseed oil and carbon pigment) onto an adjacent page or through the back of a sheet. Although this staining isn’t easily reversed, it can be controlled by interleaving pages with acid-free tissue. Repeated page-turning can also soil the pages. Oils, moisture and grime from bare fingers can impregnate the paper over time, causing discoloration and general wear-and-tear.

Both laid and wove paper can be watermarked during production. A watermark is a design formed by fine wire attached to the surface mesh of the mould. This creates a raised surface, so when the sheet is formed the pulp is thinner, showing the watermark.

Initially, watermarks were simple geometric shapes. They evolved to include logos, trademarks, signatures and customs declarations. They could also show the maker’s details, the paper grade and where and when the paper was made.

We’ve found several interesting watermarks in our collection of atlases. For example, when we examined Atlas du Voyage de La Pérouse under transmitted light, the ‘chain and laid’ lines were clearly visible, together with the words ‘F. Johannot’ and ‘Annonay’ across many of the pages. The Johannots were a family of papermakers in Annonay, France. They were second only in prominence to the Montgolfier brothers, who were famous paper-mill owners (and best known for the first demonstrated flight of a hot-air – paper – balloon over Annonay in 1783).

Other watermarks discovered in our atlases include a tower, a dovecote, and an ornate insignia of the letter ‘A’.

Online access
All the atlases in our collection are outstanding publications. We’re currently digitising these works so they’ll be available to the widest possible audience, with online access likely in the near future.

Caroline Whitley, ANMM senior conservator