Agree with Drew, you want 1/8 hardware cloth. Sometimes Ace has it, sometimes they don’t. If you need it super fast, there is a vendor or two on Amazon that sells it. Otherwise most of the bee supply houses sell it. Not plugging any particular bee company, but I usually get mine from Brushy.
Oooops, I see you're in Australia! Ace and Brushy probably don't mean anything to you. Just check out what ever bee supply companies you have in Australia. Some commercial beeks also carry hardware cloth as part of their inventory. They might have some for you.