Vallejo Gloss Metal Varnish (77657). This new Metal Varnish is specially formulated for the airbrush, dries very quickly and leaves no "fingerprints" behind. The varnish can be applied directly, but can also be diluted with distilled water or Thinner (71261). In some cases, one coat of varnish is enough; if multiple layers are needed, then best with an interval of 30 minutes between each layer. Once protected by varnish, Metal Color offers resistance to oil paint, enamel, turpentine and even light washes with alcohol.