Food Solutions New England (FSNE) is a regional food systems learning-action network dedicated to advancing a sustainable New England food system. The FSNE network is organized around four interrelated activities:
A New England Food Vision, a bold vision that calls for our region to build the capacity to produce up to 70% of food that is produced in an environmentally and socially sustainable manner, that promotes health and is accessible by all New Englanders by 2060; New England state food planning initiatives; annual New England food summits and topical workshops; and related analysis, communication and visualization.
The UNH Sustainability Institute serves as the backbone organization for FSNE. Since its inception in 2006, FSNE has advanced its mission by linking a common agenda, shared measurement, continuous communication, and synergestic activities.
Here is the spreadsheet posted by Commodity Traders International for recommended screen sizes
Here it is in google doc format https://docs.google.com/spreadsheets/d/1gPdLbwQhalAkxhQ-4isSUErvFHwqkfjdsQsCGFv6b9g/pubhtml
If you want to make your own custom screens, here is another vendor that sells all sorts of screening http://www.mcnichols.com/designer (Mcmaster Carr and other industrial suppliers also sells screen)