Lost or damaged ornamentation may need to be replaced. It is not uncommon to see ornamentation that has been inappropriately re-adhered by past restorations which would include unoriginal elements. Depending on the type of ornamentation and the extent of the damage, elements may need to be re-carved by a master carver, recast in plaster, or infilled with a reversible gesso. One common material used in the recreation of ornamentation is composition, a mixture of animal glue, resin, linseed oil, and venetian turpentine.
Once major structural treatments have been performed and the gesso layer stabilized, it is necessary to assess the bole layer of the frame. Bole is a mixture of coloured clay, glue size, and fat, which is applied on the frame as a base coat for possible gilding or inpainting.