Lee Pilgrim's plastic screens were cracked. I found the material pictured above in a scrap metal pile at the boat yard. It amazes me what boaters (especially high dollar power boat crowd) will throw away. I believe the material is 1/16" thick perforated aluminum sheet available from McMaster-Carr (here is a link - McMaster-Carr Perforated Sheets). Unfortunately it looks like this material is only available in 36" X 40" sheets that cost over $350. They also sell stainless perforated sheets, but that would be very difficult to cut to shape.
These have been installed for right at one year. I've had no issues with them in that time.
Before I discovered this material, I was considering using 1/4" starboard or 1/8" FRP sheet for the screens. Cut the material to shape and then drill 3/16" holes in the piece.