Decal softener is a mediu which protects the decal and smoothes its edges so that they blend with the surface of the model. decal softener also softens the decal to adapt it to surface detail such as recessed lines, raised edges, screws or bolts. the amount of decal softener coats needed dependes on the quality & thickness of the decal.
Final varnish can be applied to the decal if desired.