Integrity Windows from Marvin

Integrity pioneered the fiberglass window market over 15 years ago and offers two distinct series of fiberglass windows to suit your project’s performance requirements. Integrity is the world’s largest manufacturer of windows and doors made with Ultrex®, a highly durable, state-of-the-art fiberglass material that significantly outperforms vinyl and roll-form aluminum. Integrity low-maintenance products are available in two series that feature either all fiberglass construction or real wood interiors to meet any project’s performance and aesthetic requirements.

Integrity Windows from Marvin

Photo of house with many windows lit at night.

Why Ultrex® Fiberglass?

  • Strength — One square inch of Ultrex can support 34,000 lbs.
  • Superior finish — Ultrex uses a paintable acrylic finish that is 3 times thicker than competitive finishes, so it won’t crack, dent chip or peel
  • Energy efficiency — Integrity’s double pane windows are made from Ultrex with Low E coating that reduces wind heat loss and energy costs
  • Durability — Ultrex is made from fiberglass, which is highly durable, doesn’t leak or corrode, resists rot and expansion and contraction from temperature swings


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Learn More About All Ultrex Products

Download the 90-page catalog covering Integrity All Ultrex Series.

Download All Ultrex Series catalog | PDF (10MB)

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Learn More About Wood-Ultrex IMPACT Series

Download the 40-page catalog covering Integrity Wood-Ultrex IMPACT Series.

Download Wood-Ultrex IMPACT Series catalog | PDF (12MB)

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Ultrex Fiberglass

Learn more about what makes Ultrex “Quite possibly the perfect building material.”

Download Ultrex Fiberglass brochure | PDF (5MB)

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More Resources

Download Ultrex Brochure | PDF (2MB)

Download All Ultrex Brochure | PDF (2MB)

Download Commitment to Greener Communities brochure | (3MB)

Download Trim brochure | (1MB)