If you are buying or building a projector screen, you need to understand that an important element of any projector screen is a black border that surrounds the screen. While it may seem so small, this can have a dramatic effect on the quality of an image. Especially if you are projecting a high definition image, as most newer high definition projectors can provide a high level of brightness.
What material should the border be made of?
The first thing to look for with a black border is that it is made of fabric that surrounds the screen, usually made of velvet, especially if you are creating the screen yourself. Some edges are made of metal, which tends to be thin and can reflect light, so you don’t get the image enhancement effects of a quality edge. There are also some special fabric tapes that can be purchased for use with painted screens. If you are looking for the best possible image be sure to look for black fabric on all edges, certainly if you are painting a projector screen you don’t want to just paint on one edge unless it is specially made for that purpose or things may end up looking worse to dispense with a border at all.
How does a black border enhance the image?
One of the things a black border does is make an image brighter. This occurs because the difference in brightness between the image and the edge causes the brain to perceive the image as brighter. This is a very remarkable effect. One thing you need to understand is that while this may just be a perceived improvement as someone who has created a projector screen, I can tell you that the projected image without a border may look considerably faded. This is really not suitable for any type of home theater.
Another thing a black border does is absorb excess light at the edge of an image. This makes the overall image look smoother and can compensate for slightly imperfect projector settings. The edge of an image from a projector can be very noticeable, and the way light is absorbed at the edge of an image can really help with the overall immersion in your home theater system. Having a dark border that absorbs this light improves the immersion by making the border less noticeable, this is another reason why you want to use fabrics like velvet for the border.