Kevin Berni, sedak’s head of sales, explains while glass is a beautiful material, tempering and laminating can mean visual challenges, such as anisotropy.

“Almost nothing” is what sedak officials told contract glaziers, architects, consultants and others involved in the glass and glazing industry to expect. But what they found on the 101st floor of 30 Hudson Yards in New York could change how the industry looks at glass. The company used the opportunity to introduce what it says will be its new standard in tempered glass.

Beatriz Fernandez, international business development manager, Maic Pannwitz, executive vice president, and Kevin Berni, head of sales, all with sedak, welcomed guests to 30 Hudson Yards to present the company’s newest development.

Kevin Berni, head of sales at sedak, explained that while glass is a beautiful material, tempering and laminating can mean visual challenges, such as anisotropy. He added that stress in the glass can cause these issues.

There are ways to measure glass quality, and equipment manufacturers have improved processing. However, even glass that looks to be visually clear can still have anisotropy.

To illustrate this point, guests donned polarized sunglasses to view two different types of glass. The first was sedak’s current tempered glass. Without the glasses, it appeared perfectly clear. But seen through the polarized lenses, anisotropy was visible. However, viewing the second piece of glass showed no signs of anisotropy.

The company went through five years of research and development to create sedak tempered+, its tempered glass with what it describes as the lowest anisotropy.

“We are committed to ensuring that our glass addresses the evolving needs of architecture and buildings,” Berni said. “One of these needs is the elimination of anisotropies. We’ve invested extremely in research and development to eliminate these optical effects occurring during tempering. Today, we are setting new standards in glass.”

Like common tempered glass, sedak tempered+ is produced by heating the glass to a high temperature, usually around 640°C (1,184°F), then rapidly cooling it using air fans. The glass still achieves all technical properties needed for tempered glass in line with codes while providing visual clarity. sedak tempered+ is available for fully-tempered and heat-strengthened glass.

“Reduction of anisotropies sure has been of great interest to SOM and seeing sedak raising the bar with their new tempered+ standard is truly exciting,” said Christoph Timm, a principal with Skidmore Owings and Merrill’s (SOM) New York office. “Besides the improvement of aesthetics, we understand that this new level of quality doesn’t come at an extra cost to clients, which is even more exciting. I am truly hoping that other glass processors take note and also will raise their game now.”


  1. Are you describing ‘heat soaking’

  2. This is interesting. Two things: First, because we know that NYC mandates new buildings include bird-safe glass, and some older or existing ones ne retrofitted, does this product comply with that mandate? And second, is it possible that by NOT fixing this aesthetic issue, it may unintentionally lead to a bird-safe glass? In other words, might the flaw in aesthetics actually be a benefit to birds? Or does the flaw itself not eliminate reflection or fly through issues?

    1. I agree with some type of “look out, I’m glass” message for the birds. However, the key word being polarized; as in the sunglass lenses. I recently bought a car on a cloudy day, the side windows looked fine. A few days later I put my sunglasses on and the side windows were outrageously full of visual obstructions, that I found very distracting and still do…

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