Speaking as a quilter, most of the mask patterns out there are absolute hell to make. I've been using interfacing as an inner level instead of flannel or t-shirt material--but I have a lot of it (gained from a donation to the local quilt guild). Still doesn't get around the reality that mask making involves a lot of fiddly bits and all the stuff I absolutely HATE about sewing clothing (including elastic, ties, curved seams, pleats, etc).