Fig. 5

Digital optical survey micrographs (1 × 1 mm) (A) after soiling and ageing (top row) and (B) after the cleaning trials with PE-PAM₁₅ SAGs (bottom row) of (i) uncoated plaster (uc) and plaster coated with (ii) cold pressed linseed oil (CL), (iii) boiled linseed oil (BL), (iv) 6 wt% shellac in IMS (SR6), (v) 18 wt% shellac in IMS (SR18), (vi) barite with Ca(OH₂) admixture (BC), (vii) neat barite (BA), and (viii) beeswax (WX). All micrographs are (A) after soiling and ageing, and (B) after the cleaning trials with the PE-PAM₁₅ SAGs