How to Make a Rubber (Neoprene) Necklace

First, take a section of Neoprene which has been cut to a length approximately three quarters of an inch shorter than you would like your final necklace to be. So for an 18 inch necklace, you need about 17 1/4 inches of neoprene. Then, using a super glue, multi-use glue, or beading glue, apply a small amount to one end of the strand of Neoprene. Make sure that the glue goes all the way around

End Caps

Next, take a round end cap and place it on the glued end of the neoprene, making sure not to push it all the way to the top of the loop.
Repeat this on the other end with an identical end cap.

Neoprene with attached clasp

After giving the glue time to dry properly, take your chosen clasp and using two pairs of pliers, or a jump ring tool, gently open the jump ring attached to the clasp. Then, while still holding the jump ring with one pair of pliers, take your neoprene and slide one of the end caps onto the jump ring.

Pick up the second pair of pliers, and close the jump ring. It is important to get a good, tight closure to eliminate the chance of it becoming detached from the end cap. Finally, simply fasten the clasp to the cap on the opposite end of the Neoprene.