a-ha! Finally, the perfect fabric to use for a necklace like this. It's a simple project, too. Here's how it's done:
step 1: cut your fabric into strips. My camisole was cut on the bias (the diagonal) so I decided to basically make "bias tape" for my necklace. I cut long strips 3.5" wide (my beads have a 2.5" circumference). The edges are cut on a 45-degree angle. You have to cut all of the edges going the same way - this is important! Because my fabric was so delicate, I also treated the edges of all of my fabric pieces with fray-check.
step 2: to turn your shorter strips into one long strip, lay your pieces, right sides together, as shown in the picture. Sew along the diagonal .5" from the edge.
why does it matter to cut it on the bias? Well, for one thing, I didn't have much of a choice - my garment was cut this way. But it actually makes sense. Woven fabrics generally have the most stretch on the bias, so a bias-cut like this makes the fabric stretchy along its length and width. As I intend to shove wood beads down a tube of fabric, using a bias-cut fabric means that the tube will stretch a little bit, in case I make part of it too small. It's not a lot of wiggle room, but it helps.
step 4: fold your long strip of fabric over itself, right sides together (see the seam on the outside?), and stitch all along it, just a little less than .5" from the edge. Leave both ends open. When you are done sewing, turn the tube right-side out. All of your seams will now be hidden inside the tube.
step 5: now, shove your wood beads (or plastic, or whatever) down the length of the tube, tying the tube in a knot after each bead. Tie carefully, so that your knots are snug against the edges of each bead in the tube. When you are done, tie off both ends, trim, and sew shut around a clasp. You could also buy a clamp-clasp (like a heavy-duty crimp bead) and clamp the fabric ends into it, but I wanted this to cost as little as possible - namely, $4 for some wood beads.
Now I can wear that beautiful silk fabric anytime!