> Modern Pyrex ... Old Pyrex Most conveniently differentiated by the branding on the product. All caps "PYREX" is the classic (high quality) borosilicate stuf

> Modern Pyrex ... Old Pyrex Most conveniently differentiated by the branding on the product. All caps "PYREX" is the classic (high quality) borosilicate stuff. Titlecased "Pyrex" is the modern ordinary glass stuff.