ovenware that has been in business for over a century, started as a part of Corning Glass Works. Vintage pieces are still used in today's kitchens. The easiest way to identify whether your piece is antique or vintage is to examine it.

How to Tell If Pyrex Is Vintage Using Patterns and Colors
Pyrex glassware made by Corning Glass Works was originally clear. In the mid-1940s, however, colored and patterned bowls and casserole dishes began appearing and are what many collectors seek today. Pastel shades of blue, green, pink, and more became common, although bright primary colors also had their time along with more muted earth tones. The Corning Museum of Glass's Pyrex Pattern Library and Pyrex Pattern Reference from Pyrex Passion have timelines that features popular colors and patterns through the years. Just a few notable ones include:
Primary colors (red, yellow, blue, plus green) from 1945 to 1950
"Snowflakes" (both white on blue and white on black) from the mid-1950s to late 1960s..