Trying to identify PCB material

This is what I am talking about; on top is the usual, cheap, greenish one, bottom two are almost like shiny smoked glass...


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Sorry not seen that for a while and doesn't it go all brittle after a decade or two?

Can't say for sure other than I have some of it in some 40+ year old stuff I have here and it doesn't seem to be terribly brittle.

The closest I've seen to it is a paper composite copper clad board, which drills and cuts extremely nicely.

Know where I can find more details on that?


I would look for manufacturers suppliers of CEM PCB's. Not used as much these days, as FR4 boards can be purchased for the same price, with much better proerties.
CEM-1 (CEM1)- composite for PCB's - Order Online

The two boards photographed will be FR4 based, this comes in different qualities and weave patterns, so bare boards will differ in apearance, from cheap and rough looking upwards.
eBay seller identified my "nice" pcbs as "non-UV blocking laminate". I think that mine was covered with photo resist.

same thing I noticed before that it has something to do with UV.

the greenish stuff glows brightly in UV light while the white stuff stays dark.

re. Paper Phenolic; it's available here in single sided boards. all single sided boards here use that. all double sided boards are in FR4. I couldn't get FR4 in single sided. :confused: if I need single sided FR4, I peel off the other side. such a waste.