A programme of conservation began after an overall assessment of the entire RIBA Palladio collection and condition checking of the 56 drawings in preparation for the Palladio 500| exhibition.

Forty seven of the drawings by Palladio needed conserving before they could be packed for delivery to the exhibition.

Common problems associated with the Palladio drawings included:

• planar distortions, as can be seen on III/7, III/8, the condition of Palladio's drawings
• deteriorated mounts or support papers
• deteriorated animal glue
• previous historical repairs
• tears
• deterioration of iron gall ink

The conservation programme required the following:

• removal of old supports or mounts, as in case study XVI/9
• removal of previous repairs causing distortions and stress, as in case study XIV/4
• humidification, fully or locally to reduce planar distortions, as in case study X/18
• reduction of animal glue staining, removal of adhesive residue, as in case study X/4
• stabilisation of deteriorated iron gall ink, as in case study XVII/4
• new repairs
• new inlay or float paper supports
• new mounts