I used my tank top pattern to make a summer dress. My usual method of finished the edge is turn over 3/8" and stitch with coverhem. This fabric was too heavy. The neckline started pulling out of shape immediately.
I stabilized the edge with elastic. I stretched the elastic just a little bit as I zig-zagged it to the edge.
Then I turned it over and top-stitched with the coverhem machine. The dress feels very secure now.