Uneven diffuser fabric - (Starburst effect?)

<p>Hi, just bought a cheap 110cm reflector disc off the 'bay for occasional portrait/studio work. It's a standard "5-in-1" pack. I'm generally quite pleased with it - given its bargain price it appears reasonably taut and the reflector material seems fairly hard wearing...<br>

...however, when i try using it as a diffuser, the light source comes through as a cross pattern (or "starburst") effect which is also obvious in reflections on glass surfaces, eyes, etc. Is this a common feature of such diffusers or do the more expensive ones diffuse light more evenly?<br>

<img src="http://ardentcreative.co.uk/DiscDiffuserFabric.jpg" alt="" /></p>

 

<p>I've seen this difference in diffusion fabrics, but not in actual diffusion disks. My two different diffusers don't exhibit this behavior, only some cheaper ripstop nylon fabric that I bought.</p>