Moiré occurs when the pixel patterns of your projected image happen to align with the weave pattern of your screen material resulting in lines, a mesh-like pattern or even a strobing effect on your screen. Moiré is possible with woven or perforated screens which have become popular for their acoustic transparency.
Mount screen at an angle to prevent moire
Moiré is rare, but you should always test for moiré before permanently mounting any Acoustic Projector Screen Material onto your frame. It’s important to order enough material to mount your fabric at a minimum of 15°s – but up to a 30° angle. Here’s how-to calculate the amount of fabric you may need if you experience moiré:
How-To Calculate the Size of Acoustically Transparent Screen Material to Purchase
Determine the aspect ratio of your screen (4:3, 16:9 or 2.39:1)
Determine the size frame you are building in inches
Multiply the frame width by the corresponding number
Multiply the frame height by the corresponding number
This is the amount of projector screen material you should order.
Example: You are building a screen with an aspect ratio of 16:9 on a 60″x 108″ frame and you decide to order enough fabric to rotate the screen 15°s to manage moire.
Refer to the chart to find the proper calculations.
108″ Frame x 1.11 = 119.88 Wide
60″ Frame x 1.43 = 85.8 High
Order a minimum of 86 x 120 inches of Acoustic Projector Screen Material. It’s always better to have more than you need than not enough. Simply trim off the excess material after you have the material adhered to your wooden frame with a sharp scissors, utility knife or rotary cutter (such as those used by quilters).