Table 2 Varnish removal methods optimised for the lead white oil paint sample

Xanthan gum-stabilised emulsion

(78.5/20/1.5 wt.%

diH₂O/BnOH/xanthan gum)

Brush

Mixed until homogeneous with frothier. Applied with continuous stirring

3

Gel-emulsion removal via dry cotton swab rolling, and cleared with diH₂O, delivered via cotton swab rolling, as recommended by Casoli [30]

Surfactant-free microemulsion

(65/25/10 wt.%

diH₂O/2-propanol/1-butanol)

Manufactured cotton swab (Muji)

Mixed until clear by magnetic stirrer. Applied with continuous swab rolling. The swab was exchanged after 1 min of application

5

N/A

Organic solvent

(2-Propanol)

Manufactured

cotton swab (Muji)

Applied as above

5

N/A