I talked to a pre-sales person about cutting natural gum rubber and was told the S1 diode laser was capable of doing that. I was able to cut  1/8" thick sheets at 70% power and 5 mm/sec. It is not translating well to ¼" sheet. I have tried multiple passes and also 1 pass at normal focus then second pass at 2mm lower then a third pass at 4mm with further passes at 6mm. Eventually I did cut through but the result was less than acceptable. I really like the machine but if I can't cut gum rubber I can't justify the price. I know that CO2 lasers are better suited for this task but I also need to engrave brass, stainless and black anodized aluminum. Again I did ask all of these questions during a presales  conversation and was told that the S1 would work.