for more information on this woven fine wire mesh - which I have always struggled to find - I found a pretty good resource here: http://www.bwire.com -
There they tell you about open area %'s - wire diameter - wires per inch etc.
Stainless Steel is always the way to go - stays cleaner and will last for a longer time than anything else - pay more now, but less replacement later and save money in the end.
I also try to stay around the 1.2 area - most comfortable for me w the battery situation.