I stopped using Phototex for this reason, among others. That stuff stretches/shrinks too much due to heat fluctuation. I just installed a mural yesterday, printed on General Formulations 226 Wallmark. This stuff is awesome. It's 6 mil, so a bit thicker. It doesn't stretch. Install was a snap...some care is still needed when lining up your panels, but from top to bottom, everything lines up dead on. And 226 is VERY opaque and white, unlike Phototex which is nearly yellow compared to Phototex.