GMAN wrote:

Anyone know where to find the foam material that is used for filters. The kind
you would use behind computer fans and the like to catch dust. I need to make
some custom filters for a few 120mm fans, Is there some place that sells it by
the sheet or rolls?

You need fairly open stuff od the airflow will be impeded.

Do you mean this which I've used in power amps a lot (mainly present a nice trim
to cooling slots).

http://steplaw.com/reticulatedfoam.html

You don't say where you are but in case you're in the UK go to Foam Engineers for
it.

Graham