Did you ever wonder why some "lampwork" are so expensive? What make them so special besides the artistic factor? and Why shouldn't you buy those cheaper beads made in Asian countries that may look just as nice? Well, I'm going to try and answer these questions. The reason I'm doing this is not to sell my beads (although that would be a nice out come :p) but to make sure that you are aware exactly what you are getting when you buy a lampwork bead.
First thing is annealing. In glass world, this simply means cooling down glass very very slowly (for me, it's over 8 hours in computer controlled kiln) to room temperature. The vary basic science behind this is to relief stress built up within glass when it goes from liquid to solid state due to expansion and contraction. Without annealing the glass is constantly in stress and is more likely to break due to internal pressure. By annealing beads the stress are released so will be a lot less likely to break in the long run.
Now, there are a lot of arguments for or against annealing. As I've explained, annealing make the beads more durable and less likely to break. On the other hand, many people consider annealing unnecessary because glass beads made centuries ago are not likely to be "properly kiln annealed" because the lack of technology at the time. However those beads survived till today for us to wonder at their beauty and history. I'm not an archaeologist, but as far as I can find out no one really knows very much about the process involved in making glass beads in those days. So, who can say what the bead-makers at the time do to reduce stress in the glass? I personally would rather be safe than sorry. So I anneal all my beads even those destined to pave my drive way.
I've attached a picture of what a thermal crack (jargon for breakage due to lack of annealing) look like.
This bead is from my junk file and look pretty innocent isn't it? But would you still think the same if it's hanging on your neck and suddenly break in to two pieces with all the sharp edges without warning? This bead already show the sign of cracking, but many un-annealed beads don't. I just don't think it worth the risk when the problem can be prevented easily.
Next up is clean. I'm often surprised by the fact that how much gunk a bead can hold. You may not mind it, but imagine your finished jewellery that leaves grey powder on your skin and cloths. Do you still want that gunk there? This is not a dangerous problem but why put up with it when you can prevent it?