You can see that the Lauscha is hands down the cleanest clear. CIM is similar, but it seems to have more tiny inclusions (micro-bubbles?) than Lauscha. The Vetrofond bead developed a number of fairly large bubbles, but I am not sure that it was the "fault" of the glass, or me not heating the bead-release enough (the moisture in bead-release often causes bubbles inside beads). If you look closely at the Vetrofond bead, you can also see major streaks of microbubbles - which are indeed the major flaw of Vetrofond IN MY EXPERIENCE, and IN MY BATCH. Just keep in mind that just because clear behaves a certain way in my hands, it does not mean that you would have the same problems...Effetre clear has some minor inclusions, a little bit worse than the CIM clear, but less than Vetrofond.
The biggest point of attention in this test was the "behavior" of the glass after melting it off. This is important in my opinion because clear is mostly used for encasing, and depending on the method of encasing you use, you don't apply the clear in one continous application all the way to the finished bead. I often use the "dot-encasing", which means that you push a small amount of clear onto the surface, melt off, heat more clear, push it on the bead and so forth.
The worst glass in this test was Vetrofond, which developed a major "microbubbledirt-spot" at the end of the rod every single time I pulled the clear off the bead. Here is a picture of what this looks like, hope you can see what I am talking about:
This kind of "dirt" is exactly what caused the streaks in the clear Vetrofond bead. In order to avoid "contamination" of your encasing you would have to pluck the tip off the rod off with tweezers or needlenose-pliers EVERY TIME before adding more clear to the bead. The same effect by the way happened to my Effetre Batch, just not quite as pronounced. Only Lauscha and CIM burn off clear every single time.
I know that a lot of you already used Lauscha in the past, and there was always a little concern about a) the stiffness of the clear and b) compatibility. The new formula (which is JUST becoming available for purchase) is definitely less stiff and I have not found any compatibility issues.
A second test I conducted (do I ever sound like a mad scientist or what?) was the reaction of the different clears on top of silver. This might not be of interest to every beadmaker, but it's still interesting to know, AND it might explain some reactions you have noticed in your own beadmaking without being able to figure out what was going on. Here is the picture:
Two points of interest here: Does the clear influence the color of the silver foil underneath? For Vetrofond this is a definite YES - Vetrofond clear turns silver into gold. Well, more or less. This can be a major disadvantage - OR and advantage, depending on what you want to achieve. Effetre on the other hand does not influcend the color of the silver underneath, neither does CIM. Lauscha has slight hints of gold...
The second influence I noticed (and honestly, I didn't expect this to happen at all, but I repeated my test and it happened again, so I assume it IS a characteristic of the clear) is how well silver foil "holds up" underneath the clear. In this regard Vetrofond is handsdown the least "invasive". Underneath all of the other clears the silver started to burn off underneath the clear layer, and I heated all the beads as little as possible, so it's not that one bead was exposed to more heat than the others. Lauscha looks pretty sad in this test - almost all of the silver burned off underneath the clear. CIM was second worst, Effetre was third, Vetrofond the last (or "best", if you want to encase silver in clear).
One test that I haven't done yet is "clear and fuming"....there are some pictures of beads with clear and fuming in the Spotlight on Silver, but all the clears have changed formula since and might not work in the same way. Not many people seem to be "fuming" beads these days, but there is a "secondary fuming effect" when working with glass that contains silver (like Double Helix or Precision Glass). A good example is this frog (made with Precision Glass) on clear bead(Vetrofond, I THINK):
You can clearly see the yellowish tint on the clear - that is what I call "secondary fuming" - caused by the silver in the Precision Glass. This effect is most pronounced on ivory (as explained on the January page of my calendar) - and a test would determine whether each of the different clears "accepts" the fuming in the same way, or whether there is a clear that is immune to the silver fume...something to try in the near future.
One more remark: Clear glass has quite a wide range of prices, which also might determine which one you want to work with. The following prices are current prices at Frantzartglass - I assume that they differ from supplier to supplier, my apologies if I don't give you a complete survey of prices, but I am sure you have your own favorite supplier already, and you know where to get the best deals. All prices are per pound:
Vetrofond Crystal Clear: $ 9.00
Effetre Clear: $ 11.00
Creation is Messy: $ 23.00
Clear SOFT Lauscha: $ 29.00
(not tested: Precision Clear $ 38.00)
Conclusion: Make up your own mind what feature is important to you, maybe have a few different clears on hand for different purposes, and then pray with me to the Gods of Glass that Someone, Someday will come up with a clear that is PERFECT in all regards, and costs 5 bucks a pound.