The Perfect Window Material

Ultrex, a patented fiberglass that just might be the perfect window material. Ultrex is tough. It outlasts vinyl, roll form aluminum, and other fiberglass composites.  It won't corrode, it's low maintenance and it's beautiful. Marvin pioneered this revolutionary material and have nearly 20 years of experience working with it. Marvin used this time to perfect their manufacturing processes, making Ultrex the best fiberglass window you can buy.



Marvin makes Ultrex with a special process called pultrusion. Thin strong cables of glass are saturated with special resin compounds then pulled through a heated die to form the final window components. Our patented pultrusion process creates a material so strong that we have to cut it with diamond tip blades. Ultrex is eight times stronger than vinyl and as strong as steel. Because it's so strong we can build our windows with a thinner frame profile. That gives you larger glass area for better views.

They can withstand temperatures from 40 below - 350 above with virtually no expansion or contraction.


Ultrex Finish

Ultrex meets all the requirements of AMA 623 – 10. This means that Ultrex has been tested with acid, baked in a hot oven, and placed in extremely cold temperatures, with no corrosion blistering or peeling. The Ultrex finish is also the first and only window material on the verified components list of AMA 624 - 10 and 625 – 10.


Vinyl and other materials will expand and contract. Over time that can

cause your windows to fail, but Ultrex is as thermally stable as the glass itself.  Ultrex it expands 833 percent less than vinyl and 300% less than wood vinyl composites.


Ultrex Acrylic Cap Finish

Our acrylic cap finish is actually bonded to the fiberglass.  It's up to three times thicker than the competition's thin painted finish and resists fading, scratching, and chalking.


We're putting on a thick film of acrylic material. We extrude it straight on to the product. It doesn't have any of the typical problems associated with paint where we have thin spots or runs, or drips or orange peel. It's a real consistent finish. When we're manufacturing the product, we don't have to worry about it getting nicked up, or when an installer is putting a window in, it can take a little bit more abuse than a typical painted finish.  – Thomas Gohdes, Director of Engineering



We're so confident in the performance of Ultrex windows that we offer them in dark colors. Ultrex resists the sun's ultraviolet rays five times better than vinyl.  It stands up to every climate; East Coast, West Coast, or anywhere in between. Ultrex can take whatever the weather dishes out - in sun, rain or salt air.


The Perfect Window

Tough beautiful Ultrex outlasts the competition. The final product is a durable, structurally sound, long-lasting product that is better than anything else in the industry.


INFINITY provides home comfort and energy efficiency — no leakage, no drafts, top thermal performance.
• Tested to rigorous industry standards for thermal and structural performance
• Comes standard with high-performance Low EII glass
• Meets ENERGY STAR® in all regions
• Infinity can reduce your annual energy bills by 33%


Low maintenance, durable, will look good over time.

• INFINITY’s Ultrex fiberglass is 8x stronger than vinyl
• Ultrex fiberglass is virtually maintenance-free
• Ultrex fiberglass is durable – won’t rot warp, dent or fade

material strength infinity windows


INFINITY is attractive, easy to operate, and easy to wash.

• A narrower window profile allows more daylight and better views
• Infinity windows have innovative features for cleaning from inside the home
• Designed to replicate the details and beauty of traditional wood windows


Peace of mind, no-hassle experience.
• Simple, hassle-free sales and installation by trained, local window experts
• Transferable warranty
• INFINITY is backed by Marvin Windows and Doors, an industry leader since the 1930s

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total value for infinity windows


Satisfaction of the best windows for the best price.
• INFINITY offers superior performance, materials, appearance, design, reliability and expertise
• All these features at a competitive price
• Ask your sales representative for more details!

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