I've made a plastic frame (for the the filter) for my air return and want to cover it with a good material to eliminate as much of the "goop" that flows thru the air as possible. I've been told that electronically charged material ( I was told this would be a generic for the Filtrete by 3M). In any event, I haven't a clue where to find material that I can cut to size. Any suggestions anyone? Thanks. Betty