I am evaluating a couple products -- lighting ballasts -- and noticed one of them seems to use G-10 as the PCB laminate. I assume that the beige, solder-mask-free top layer is the clue.
Given that FR-4 is Flame Retardant, whereas G-10 is not, I prefer to stay away from the latter laminate. But I cannot say for sure if the second board uses FR-4 or not.
It appears that the second board has more of the FR-4 look to it (that pale green), but that could just be a top-layer solder mask.
Am I on the right track here? Is it even possible to tell the difference between G-10 and FR-4 like this?