another twist-core

[Gustav]

Originally Posted by DaveS

I was fairly sure that the first kind of pattern was done with a deep
acid etch, but the second type with the threads of nickel has to be con-
structed the same way as any type of Indonesian pamor. I can't see that
it could be done any other way.........Dave

oncemore -

both kinds (actually there is only one kind) are done like a normal Pamor from Indonesia or Malay Peninsula, using iron with some nickel % or some other element, which would react differently with acid.

The difference here is only the method of etching - topographical (like described by Newbold - a strong etch) or a normal one.