Interesting story- I used to install windows for Thermal Line Windows who are the ones who developed compozit in association with GE Plastics. They were gobbled up by THV a few years back. THV did away with all of TLW's old window profiles leaving all our customers holding the bag when they needed replacement parts when they did away with their vinyl line and developed a whole new line of windows using compozit. I'm not a big fan of them. Compozit lacks the flawlessly smooth surface that vinyl has... it does show some lines in the profiles from the extrusion process, which is something that drives me nuts. Compozit's advantages are mostly in dark colors like dark brown where the window gets hot. A white window reflects light and would not get as hot as a dark window in the sun. We also experienced some problems with the compozit being brittle. Yes it's stronger than vinyl and more rigid, meaning the frames can often be less bulky. The slider version of the compozit window had problems with the rollers beating up the track that they ride on. We never had that problem with TLW's old vinyl monorail slider that slid on velcro pads, not rollers. What a nice window that was. Thanks THV for discontinuing them. IMO if you only want a 15 yr window go with something that is still a good quality, but less expensive.

Thank you. That's exactly what I needed. You're right, having the proper name helps.