I noted Dave Hoover's response to the question about d.s. and he suggests
resin souyrce as the reason for variability between vendor "A" and "B".  I
would suggest other possibilities such as treating tension, fabric tension
control at the weaver (also lot to lot!), etc.  Unfortunately there are
probably also phantom variables.

Dave, a question.  What is the magnitude of the "A" vs "B" vendor difference
in d.s. with for example FR-4?  Anybody else have any data (or gut feel)
regarding the between-vendor variability for the "same" resin system?

Chet Guiles
Arlon