There are three types of projection materials:
• Those intended for front projection
• Those designed for back projection
• Those that work for both font and back projection.
While there are materials that have been specifically designed for projection like the common Gerrietts products “Opera”, “Revue” and “Studio” there are many other fabrics is common use for projection, such as muslins, scrims and gauzes. Sharkestooth scrims are particular versatile and popular with designers. I have also projected on many walls and flats that have been painted to serve as projection surfaces.
Products that have been specifically designed for projection applications have characteristics that can looked up in the manufactures catalogue. the main characteristics are:
application: refers to the materials suggested use. examples are back projection, front projection, front and back projection, diffusion of LED screens.
color: refers to the inherent door of the material common colors are white, cream white, grey, black
opaqueness: refers to whether the material is translucent or how much can be seen through it.
gain: refers to how much of the original light projected onto the material will be reflected back. A gain of 1.0 means that the material reflects as much light bak as is projected onto it. Note that high gain often comes at the expense of wide viewing angles.
viewing angle: refers to angles at which a spectator faces or looks at the screen or at which angles the screen is relative to the viewer.
Gerriets has useful diagrams for each materials that show how well an image on the screen can be seem relative to 0 degrees which is straight on. this can also be described as the gain falloff relative to viewing angles
Flameproofing: refers to the fabrics abilty to withstand fire. Safety norms for fabrics and materials used in public events vary from country to country.
Materials and Fabrics that have not been specifically designed for projection can be measured against these same criteria. However no tables or specification sheets exist for them. The way I determine whether a particular fabric or material is a suitable projection material is through testing and demoing. Only this way the adequateness for a particular application or project can be established.
One of the most common projector materials is the humble wall or flat covered with paint.
It is therefore useful to know that there are paints that have been specifically designed for projection applications. These again have predicable characteristics. Regular paint does not. That is in part because it reflects different parts of the visible spectrum of light in unpredictable ways and it comes in shiny (or gloss), matt and semi-matt.