epoxy glass FR-4 colors and where to find them

[neazoi]

see this picture. When I print PCBs, most of the FR-4 I find is the bottom color one.
I would like to find the left one. This was used on older PCBs (70's 80's).
Any ideas what to find them and how these are called? (if they have a special name)

 

[KlausST]

Hi,

never thought about the color of the FR4 base material...

Usually the color of a PCB is dominated by the solder resist color.

Maybe the base material color really is different, but there also may be other reasons:
* copper plating or not
* blackened copper traces (Some decades ago one chemically blackened copper traces for better solder resist bonding. Maybe they also blackened the base materieal side of the copper. Don´t know)

 

[neazoi]

Hi,

never thought about the color of the FR4 base material...

Usually the color of a PCB is dominated by the solder resist color.

Maybe the base material color really is different, but there also may be other reasons:
* copper plating or not
* blackened copper traces (Some decades ago one chemically blackened copper traces for better solder resist bonding. Maybe they also blackened the base materieal side of the copper. Don´t know)

These old PCBs I am aware of, did not have a solder mask at all. The traces were either gold plated of tin plated and the FR4 was bare, no solder mask.
I want to see if I can re-create the vintage look of these PCBs, with this nice blueish-greenish FR4 color.

 

[FvM]

Even datasheets of major FR4 vendors (e.g. Isola, Panasonic, Tapco) have no specification of laminate color. I still see greyish laminate at some PCBs, but obviously we have other criteria for selecting substrates in professional design.

I would ask PCB manufacturer or DIY shops if they have PCB substrates with specific color available.

--- Updated Oct 5, 2021 ---

GFK laminates are specifically made for other purposes than PCB, e.g. 3D-printer support and general mechanical applications. Some with bulk coloring.