Humidification processes were used to address the planar distortion of sheet X/18,
Plan of the Villa Madama, Rome.
In humidification a Gore-tex® membrane is used to prevent the object from getting wet as the water vapour migrates through the membrane, penetrating in a gas form only. This factor makes it a perfect material for the use of humidifying paper-based objects in conservation. The sandwich allows the humidity to flow until equilibrium is reached within the paper. As long as the temperature is stable, no condensation will occur.
The sandwich can be modified according to the requirements of the object. For example, with sensitive media or pasted sheets, as in the case of X/18, a single sheet of Gore-tex® can be used to ensure that the object is only lightly humidified on the one side. This is shown in the two diagrams.
Sheet X/18 was not allowed to become wet during humidification as this might have resulted in the off-setting of the ink media. Once damp the sheet was dried using drying felts.
Bondina, a synthetic non-woven support fabric, can be used to add additional protection covering the drawing material during the drying process. If the drawing had been dried in the open air distortions would have occurred.
The drawing was inlaid prior to the object being mounted and framed for the Palladio 500 exhibition.