1. The projector and screen are linear, please try to project the projector directly in the center of the screen This is a reflective screen, It works by reflecting light back to where it was emitted. 2. This Screen adopts high-density fiber material, no smell, and no harm to the human body and health. 3. Usually, we will cut the size of the screen a little bigr, if have a 1-3 cm deviation, wish you don't mind it, The measurement allowed error is +/- 1-3 cm. 4. So you won't t the best viewing if the projector isn't positioned at a specific angle. 5. The viewing angle is about 30-40 Degree.The metal layer and the bead particles in this screen will increase the brightness.Give you a better experience for watching.