wide angle diffuser
 

looking for a source of WA diffuser material - similar to the plastic diffuser which fits over a flashgun - the type which has a triangular ribbing texture in vertical columns

need a piece by 4x4 inch

any suggestions?

What temperatures will this have to withstand, what wattage and how far away from the lamp?

The material you describe would melt next to a hot light.
Tuff spun is a diffusion filter, it's cheap but it doesn't last forever. The upside is a 20x24" sheet costs less than $6

For hot lighting diffusion try Lee filters US site
http://leefiltersusa.com/PDFs/Lighting/LightPdfIndex.html

or Rosco
http://www.rosco.com/main.html

Most big camerta equipment suppliers carry Lee or Rosco

http://www.bhphotovideo.com/bh2.sph/FrameWork.class?FNC=ProductActivator__Aproductlist_html___44001___RO3006S___REG___CatID=1329___SID=F 4C664ACBE0___call=specs#goto_specifications

thx Bryan

temperature is not a problem

unfortunately frosty and spun dont float the boat

its the ribbed type i am after about 2-3mm pitch

theres nothing quite like answering your own question...

it appears the material i am searching for is called a prismatic diffuser available as small pyramids or triangular grooved and is usually used in drop ceiling lighting ( i knew this -arghh !!!) and can be obtained from diy hardware stores in panels of various sizes and is used to kill the hotspots in lighting for a wider even coverage

so now we know...

How do the triangular grids used with flourescent light banks do in comparison to common diffusion materials such as tracing paper and grid cloth ? I'm using a few 4-bulb troffes and am
wondering if i should use the included pyramid diffusor sheet
or replace/augment that with other material.

At my new work place, I don't see the
standard troffe fluorescent light banks mounted in the ceiling.
Most of the lighting is suspended about two feet below the
ceiling and pointed up so that the light is bounced off the
ceiling.