Corning Ware Platter P-19 P19 Blue Cornflower Meat/Roast Dish

• Platter: 16.5 inches long x 10.25 inches wide x 1.25 inches tall

**It's important to note that these dimensions might have slight variations due to the handmade nature of vintage Corning Ware. See pics for exact measurements.**

While Corning Ware was first introduced in 1958, the P-19 platter in the Cornflower Blue pattern was likely manufactured in the late 1950s to mid-1970s.

Here's why it's hard to give an exact year:

• No specific date markings: Corning Ware didn't typically include year markings on their pieces.
• Long production runs: Popular patterns like Cornflower Blue were produced for many years.  
• Variations over time: There might be subtle differences in the shade of blue or the backstamp that could help narrow down the date range, but this requires expertise.

Corning Ware P-19 platters were made of a remarkable material called Pyroceram.

Pyroceram was a unique glass-ceramic material invented by Corning in the 1950s. It was incredibly durable and had amazing thermal shock resistance, meaning it could withstand sudden changes in temperature without breaking. This made it perfect for oven-to-table serving and even freezer-to-oven use.  

Here's why Pyroceram was so special:

• Strength: It was much stronger than regular glass, making it resistant to chipping and breaking.  
• Thermal shock resistance: You could take it from the freezer and put it directly in a hot oven or on the stovetop without worrying about it cracking.  
• Non-porous: It didn't absorb food odors or stains.  

Pyroceram was a key reason for Corning Ware's popularity in the mid-20th century. It was truly a revolutionary material for its time!

However, it's worth noting that newer Corning Ware is often made from a different material, usually stoneware. If you have a newer P-19 platter, it might not be Pyroceram. You can usually tell the difference by looking at the bottom of the dish. Pyroceram has a smooth, white, and glazed bottom, while stoneware often has unglazed areas.  **This one appears to be made of Pyroceram, but I cannot guarantee that, although the bottom is glazed as can be seen in pics.