The flattening

It allows for the restoration of a stable form to supports deformed by time, humidity, folds, mechanical stresses or conservation accidents, while facilitating their study, digitization and manipulation.

Beyond its practical aspect, flattening is truly important for conservation: it reduces internal stresses, improves legibility, avoids repeated handling, and prepares the artwork for safer storage. When carried out properly, it therefore contributes as much to the physical preservation as to the heritage value of the object.

For works on paper

The principle is similar, but the techniques vary depending on the nature of the inks, pigments, and materials. Controlled humidification can be supplemented, when the artwork allows, by a wet treatment or bath, which helps to relax the fibers and remove certain impurities or degradation products. However, these methods require preliminary testing, as they are not suitable for all documents and may be incompatible with some sensitive inks.

 

For the parchment

This operation requires great care, as the material reacts strongly to humidity. Direct water application should be avoided; therefore, controlled humidification, either in a chamber or via an indirect system, is preferred to gradually soften the fibers without causing warping, excessive shrinkage, or new tension. Depending on the condition of the piece, the process can then continue on a vacuum table, with light tensioning and controlled drying to maintain lasting flatness.

Intermediate materials such as Gore-Tex or other technical textiles can also be used in indirect humidification systems. They help create a stable microclimate by allowing moisture to diffuse gradually and evenly, without direct contact with water. This approach offers better control over the treatment and reduces the risk of damage to delicate surfaces.

 

What is Gore-Tex © ?

It is a chemically inert material, relatively insensitive to solvents, with pores 0.1 μm in diameter. Liquids are therefore diffused through this membrane only in vapor form.