WOW! Thanx for finding that. Their description sure sounds like the stuff that I (think I still) have. Their tech specs seem peculiar though. That the treated layer is >>>
Flashed Opal Layer Thickness:
0.45mm (+0.35mm /-0.20mm)
Which seems crazy thick and crazy variable to me. I sure recall it being much thinner, but could be mistaken. Hopefully, I can find my stash out in the barn and measure it somehow optically. I thought the thickness was like a handful of microns... but maybe I'm just a dope. Or maybe B&L ordered ~select thin~ or even made their own?! I'll research that some more and then also call them tomorrow. Well, their description that the bulk sheet simply is not produced anymore is certainly consistent with my recollection.
This is just my personality --- I'm suddenly panicked that I may not be able to find my stash of Single Surface Fire-Flashed Opal Glass, or that I won't ever be able to get more "Just In Case". In case what, I haven't the slightest idea, but I won't be able to sleep until I know we have that material in a box under the bed.
No wonder my employers treated me well --- I was probably the only optical scientist who obsessed over optics to the point of being a mental case... quite useful in the Research Labs. Igor was my best friend. Tom