Just like working on canvas, a varnish can be applied after the work has completely dried (9-12 months). In the interim (after drying for about 6-9 months), it is possible to revive any discoloured areas using the Talens 004 Retouching Varnish. When working with thick layers of paint, it is wise to eventually glue the paper onto a hard surface. Oil paint becomes harder over time. On a firm surface, the paint has less chance of cracking (craquelure).