I made a bunch of variously shaped "Riccia Weights" a while ago and never used them. These were done like Brigit's famous Riccia weights.
They are made of 3/32" 316L Stainless steel
You are probably not familiar with 316L but rather the common 304. A few notes on each
304 The most widely used form of stainless steel. It also has good formability and corrosion resistance. 316 High nickel and molybdenum content can provide excellent resistance to corrosion and pitting 316L More corrosion resistant than Type 316, it's ideal for high-purity processes
ie, I picked the best material I could get my hands on without breaking the bank