Undulations / Buckling / Wrinkling / Cockling:
Uneven deflection of a flat surface of usually flat 2 d materials such as mats, textiles, barkcloth, canvas paintings, paper and vellum.
Object has sustained significant amounts of damage making its structure unstable or with extensive losses or breaks and is at risk of further damage.
Unsupported paint ledge:
Where gesso or material underneath paint layer is eroded away leaving jutting paint layer.