Flammable fabric treatment on the Blackburn Blackburn

What was used to dope the skin of the Blackburn Blackburn?

A highly flammable fabric treatment, although its exact composition is not recalled.

The treatment applied to the Blackburn Blackburn's fabric skin is described as highly flammable. That property is associated with the doping materials used on aircraft fabric of the period. The exact chemical mixture is not recalled, leaving the formulation unidentified.