Is it true that perforated screens are not suitable for DLP, LCD, and other fixed pixel projectors?

Yes, the perforations in standard vinyl screens interfere with the pixel patterns of projectors. This results in a distracting pattern effect called moiré which contains repetitive details such as lines and dots that exceed the sensor resolution. As a result, the image clarity suffers and produces a strange-looking wavy pattern, distracting the viewer. Screen Research ClearPix products use fabrics woven from proprietary fibres to avoid this interference and to produce a moiré-free image.