Three Unbreakable Layers: The Secret of Corelle

As I walked onto my deck, dinner in hand, ready to enjoy a beautiful summer evening, I looked at my plate and suddenly remembered that my blog on Corelle was due. Dinner would just have to wait.

Like many people, I suspect, when I think of Corelle, I remember eating outside in the summer as a child, sharing family meals around the table, going to potluck dinners, and other pleasant memories. But unlike many people, I suspect, I can’t not think of the incredible science and technology behind Corelle.

This year marks the 50th anniversary of the invention of Corelle. To celebrate the occasion, The Corning Museum of Glass presents Dish It! Corelle at 50, an exhibition taking you behind the scenes of one of America’s most cherished brand names.

Known for its simplicity, beauty, practicality, durability, and affordability, Corelle is also a stackable, classy, and glassy dinnerware that comes in more sizes, shapes, and patterns than you might imagine. Dish It! explores the people behind the plates and patterns, how the dishes are made, and the scientific secret to Corelle’s legendary toughness. This latter I can shed a little light on here, but you’ll have to visit to get the full story.

Vitrelle glass, the name for the glass used in Corelle Ware, consists of a 3-ply laminate: a thick core glass-enclosed on top and bottom by a much thinner glaze or skin glass. The result is a lightweight durable plate that is carefully designed to inhibit breakage. That durability is achieved in two steps.

First, the lamination process makes each layer have a stress opposite to the stress of the adjacent layer. That is, the skin on the top and bottom are in compression (the atoms are being squeezed), whereas the core is in tension (the atoms are being pulled in opposite directions). By itself, lamination produces a plate that is impact resistant. But this result is not enough to eliminate delayed breakage, when small cracks propagate over time, leading to catastrophic failure at unexpected moments, such as while a dish is being washed or just resting on a shelf.

Pretty clearly, this should not happen, so there’s a second step to take care of that. In this step, the tempering process, the depth of the compressive stress layer is deepened considerably, making the product more durable because it prevents delayed breakage – any breakage is engineered to occur immediately instead.

Information labels from the exhibition, Dish It! Corelle at 50.

The core of Vitrelle glass undergoes crystallization either spontaneously as the glass cools, or when the glass is heated in the tempering process. This crystallization transforms clear glass into a light-diffusing opaque glass. The final product is, from a material science perspective, a glass-ceramic. What you see as opal white glass is the core glass, which you don’t actually touch because it’s covered by the thin clear skin glass.  

The ink used to create the patterns is a glassy ink. Because it’s fused onto the skin glass, you can actually feel the pattern. In fact, if you have more than one Corelle pattern at hand, you might try this sometime: have a friend close their eyes and see if they can describe the pattern using only their sense of touch. Or try it yourself; you might be surprised at the result. As I try it myself, I’m not surprised that my food has gone cold. I’m glad the plate is Corelle; I’m just going to put it in the microwave and enjoy my dinner now.  

Dish It! Corelle at 50 is now on view in the Innovation Focus Gallery, a small gallery within the Innovation Center. At this time, max capacity within the gallery will be three people, providing a nearly solitary experience when viewing this exhibit. Plan your trip and make reservations to visit in advance by going to

7 comments » Write a comment

  1. It would be nice if there were actual pictures of corelle objects. I can’t seem to find any!

  2. Interesting!
    Do you have any information on Dicore? That’s the corning glass used for anterior crowns in the 80’s. It was all returned to the manufacturer in the mid 80’s. What is the history behind it?

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