Evaluation of novel cleaning systems on mock-ups of unvarnished oil paint and chalk-glue ground within the Munch Aula Paintings Project

Heritage Science

Table.5 Summary of the observed effects and efficiency of the novel cleaning systems on the M2 mock-ups

System	Mechanism	Cleaning efficiency	Associated risks to paint/ground layer	No, or low risk of
Dry PU sponges	Mechanical	Minimal to moderate	Pigment loss/removal, scratching/polishing, undesirable gloss change, re-depositing and embedding of remaining soiling particles	Cleaning system residues
SPB	Air abrasion	Moderate to satisfactory	Pigment loss/removal, abrasion, undesirable gloss change, cleaning particle residues	Integrating remaining soiling particles
CO₂-snow	Air abrasion/chemical	Minimal	Pigment loss/removal, undesirable gloss change, condensation, re-deposition and/or integration of soiling	Cleaning system residues and scratching or abrasion
Nano-gels	Mechanical/chemical	Good	Pigment loss/removal, staining, swelling, leaching, possible metal soap formation undesirable gloss change, integration of remaining soiling particles, cleaning-solution residues	Scratching or abrasion