Abstract: A composition and method of application of the composition to produce masks of the type particularly useful in the manufacture of varnished electronic terminals and components is specified. The composition consists of mixing acetone, nitrocellulose, methyl isobutyl ketone (MIBK), arylsulfonamide formaldehyde resin, and tri (b-chloroethyl) phosphate, a fire retardant, under carefully controlled conditions. This masking product is applied, prior to the varnish, on an electronic part and is subjected to heating in the varnish curing oven to about 200.degree. F. whereupon the masking product will carbonize. The resulting carbonized coating is easily removed by brushing to produce a varnish mask where the masking product was applied.