A couple of weeks ago, I said I would buy these and report back to the group with my results. here ya go:
Clamshell bead tips, sometimes called Fold-Over Bead Tips, are designed to completely hide the knot at the end of a strand. When the halves are together, it looks like a round bead. Usually, I put a seed bead in the metal bead tip and dab it with a touch of crystal cement to make sure the knot doesn't slip out of this finding.
The normal clamshell bead tips have one loop or ring at the end of the "shell" part, which is meant to attach to a jump ring or similar finding. Some of these bead tips have an open hook of metal, which can be bent into a ring shape. They also come in a variety of metals - I only use Sterling Silver or Gold Filled, as I have found that base metals just don't do it for me.
These new clamshells have a 1 mm loop on both sides of the "shell," that looping metal is unneccessary. Once a Jump ring is secured through both holes, it would be quite difficult for the clamshell to open up, so the bead strand would be much more secure.
Today, I got a chance to try the new bead tips. I found that they are everything that they are advertised to be, and a huge advance over the older kind of clamshell. The finished ends are much more professional looking, and with my customary drop of watch cement, these things aren't going anywhere. They're about 50% more expensive than the hook kind of clamshell tip, but that only added about $0.30 to the cost of my necklace. For the extra security, I can live with that.
I've only seen these heavy duty clamshells at Rings and Things
Your intrepid reporter,
Kathy N-V