Size of perforation / size of webbing?

The minimum perforation size needs to be at least 2x the material thickness. So, 3/8” opening on 3/16” material. There is no max perforation size, except where code dictates – e.g. 4” sphere rule for guardrails. The webbing or material between perforations also needs to be 2x material thickness or greater for strength and to reduce deflection on the panel face. Long slots that cross most of a panel face can weaken the panel and may not be workable without modifications to ensure panel integrity.