← Permanent-wave history: overview and related inventions
Research status: the distinction between documented patent claims, technical interpretation and unresolved questions is intentional. A named system is not automatically evidence of a unique invention.
Moving away from heated machines
Cold-wave processes changed the balance between thermal apparatus and chemical treatment. The central historical question is how the chemistry, application and neutralisation differed from heated permanent-waving methods.
Arnold F. Willatt and the historical transition
Willatt is commonly associated with the development of modern cold-wave practice. Specific claims of priority and exact introduction dates require patents, trade publications and contemporary documentation.
A branch, not merely a better heater
The cold wave was a different technical solution to the problem of lasting hair shape. It should not be drawn as a direct refinement of one particular electrical heater.
Questions for further documentation
Which formulas and neutralising procedures were used? How were salons trained? When did the method become widely available? These questions require dated primary sources.
Original sources still needed
- Original cold-wave patent specification
- Contemporary chemical manufacturer instructions
- Period advertisements and professional training manuals