https://www.darbywiremesh.com/brass-wire-mesh/
Here's one source. They handle any size mesh you want. The screen I used was given to me and unfortunately I do't know the source. Graingers? The mesh size I used is not real fine, but fine enough to keep the big stuff from plugging the shutoff valve and gas line. Don't use steel screen, because it will rust. Brass conforms easily to any shape you want, and is easy to solder.