This section is from the book "The Tinman's Manual And Builder's And Mechanic's Handbook", by Isaac Ridler Butt. Also available from Amazon: The Tinman's Manual And Builder's And Mechanic's Handbook.
Sandarach, four parts, mastic, seed-lac, white turpentine, of each two parts, gum elemi one part, alcohol twenty-eight parts. Digest with frequent shaking, and filter. Before applying this varnish, the paper must be twice painted over with a solution of white gelatine, and dried.