I am not exactly certain where your reference came from but about 50 years ago one of the methods explored for fabricating PCBs was to flame spray the circuit pattern onto a dielectric substrate through a stencil with a circuit pattern in it. There was a photograph of it in a publication called "Printed Circuit Techniques" which was printed by the Government Printing Office in 1946. That picture was included in an early IPC video " The Electronic Interconnection" .This brings me to a question of my own. Does anyone have a copy of this publication somewhere in their archives. The GPO can't help. It is of some historical value for those of us who are collecting information about the early PCB industry. I had a copy once, about 12 years ago, along with the book that followed the year after which was call something like "Advances in Printed Circuit Techniques" but I gave them to a friend and they can't locate them. Both books were short I think less than 50 pages. I would like to get a photocopy of the books if anyone has them in their library gathering dust. Cheers, J.Fjelstad