It is difficult to retouch/inpaint paint losses on the painting painted on absorbent surfaces i.e. cardboard, painting boards and similar. Solvent and medium are absorbed and discolour the support making proper assessment of colour matching impossible until the solvent evaporates. The same problems occur when retouching matt, absorbent paint, tempera or gouache. Retouching medium and pigment are absorbed and migrate into the surrounding paint causing permanent discolouration and drying rings.
B72 Retouching Gels retain solvent and resin within their liquid crystal structure and therefore the undesirable migration and discoloration of absorbent support and/or matt absorbent paint is avoided.