This is not directly related to thread size, but rather is based on the tension of the first two rows of your beading project. For a looser bag, keep the tension loose (leave about a bead width or two of space when tying the beads for the first two rows into a loop). For a tighter weave and a more stable fit on your lighter, snug up the tension by leaving less (or no) extra space. Time and practice will allow you to find your preferred balance, so be sure to do several beading projects!
