Scrim, also known as gauze, is a strong, coarse cotton fabric with a rectangular weave. This gives it the appearance of a window screen. The material is most commonly used to make curtains, but it’s also used for upholstery, bookbinding, and special effects in theater. Sharktooth scrim is the name given to it when it is used for this last purpose.
Because scrim is lightweight and translucent, many people believe it is an ideal material for curtains. When lit from the front at a diagonal angle, it can appear opaque, but when lit from behind, it becomes transparent. This property makes it particularly useful in theater, as it can be lit from the front to obscure the audience’s view of what is happening on stage when scenes are changed. When the fabric is lit from behind, the audience can see what’s going on behind it once more.
Although scrim and another material known as bobbinette are often used interchangeably, they are not the same. The hexagonal and wider weave of bobbinette makes it more difficult to conceal the appearance of objects when used in the theater. Scrim can also be used with a cyclorama, which is a large theater curtain. The projected images become easily visible when the cyclorama is lit, and then vanish when the material is no longer lit. The projected image appears to have depth when the two fabrics are used together.
You can also get a moiré effect putting one piece of scrim cloth behind the other and lighting them on stage. When two grid-like patterns are stacked on top of each other at an angle, this effect is created. When using fabric for this effect, the audience may feel disoriented while watching a scene on stage.