I would like a respirator with replaceable cartridges, both for organic vapors (painting, etc.) and dust protection while woodworking. I have tried the disposable paper masks, and don't like the poor fit to my face. I also have two different respirators with replaceable cartridges that I got at HD and Lowe's, but the thing I don't like about them is the narrow elastic straps that hold it to my face. They stretch out from the weight of the mask and I frequently have to re-tighten them. Is there any respirator out there that doesn't use the cheap & flimsy elastic straps? What do you pros use that have to wear respirators hour after hour?