[wyclif]

Thanks, I'd never heard this before. Do you know of any sources for vintage Pyrex?

[wyclif]

EDIT: I just found out that one of the ways to distinguish the earlier, borosilicate Pyrex is that the earlier versions are labeled in all-caps: PYREX.

[quercusa]

The new stuff is also noticeably greener (e.g., look down the side of a measuring cup so you are looking through as much glass as possible).