I am working on a design for a solar dryer but I not been able to find a definite answer to what food grade screening is. So far I have read just regular window screens, galvinzed, plastic coated and the list goes on.
I was hoping to pick some up today at the TSC store.
Thanks
I'm thinking that if you were to get some pantyhose or nylons to use as screening, it would allow air flow and keep out even the smallest nasties.
Those who are unwilling to defend freedom, will become unfree.
Stainless steel for sure. Glass fiber possibly.
Maybe galvanized but I don't think it handles acids too well. Probably not plastic. It doesn't do heat very well.
Try this
http://www.twpinc.com/wire-mesh/TWPCAT_12
Google search has become so much about sponsored adds I don't have much luck there anymore.
I saw an old episode of Ma & Pa Kettle once when Ma put a bunch of oranges in one of the nylon socks (clean I hope 😯 ) and ran it thru the wringer of the washing machine. 
"We 'Prep.' to live after a downfall, Not just to survive."