If a waterproof stiffening is required use one of the varnishes for which formulas follow:

I

Copal...........     450 parts

Sandarac........       75 parts

Venice turpentine      40 parts

Castor oil........         5 parts

Alcohol.........     800 parts

II

Shellac.......... 500 parts

Sandarac........ 175 parts

Venice turpentine 50 parts

Castor oil........ 15 parts

Alcohol.........2,000 parts

III

Shellac.......... 750 parts

Rosin........... 150 parts

Venice turpentine 150 parts

Castor oil........ 20 parts

Alcohol.........2,500 parts