For this post, I thought I would answer a question I got in a comment on my last entry.
In the previous post, Purple Plaid Rings, I talked about the fact that the finish wore off of some of the beads that I used. I think it is important to note that I used the same beads for the bracelet, and they took a lot longer to wear than the rings did. A necklace would take even longer, and sculpture, if kept out of direct sunlight, would probably be OK.
Please understand, that I am not an expert, I am just speaking from my own experience.
That said, galvanized beads are plated with zinc, and that plating will wear off. Any bead marked dyed, will not be safe with out sealing. The problem is that a lot of companies do not mark which of the beads they carry, are dyed. My personal experience is that silver-lined can also be an issue.I have found that when I am working with silver-lined, and using beeswax as thread conditioner (you should always condition any thread you work with, that is not preconditioned), that if I keep having to do the frog stitch (rip it rip it, out) I will wear the finish right out of the bead. If I do not have to rework a piece over and over, silver-lined seems to do fine, once the piece is finished.
Beadies Beadwork (click on their name for a link) has a good description of the finish on Delica (c) beads. I feel like, at some point, there was somebody else out there with good descriptions and warnings. I will look for that and if I can find it, post it later.
After you have had a bead around for a while, one thing to look for is, has the baggie it is stored in started turning the color of the bead. If so, that bead has been dyed.
But truly, the only way to know for sure, is to test them.
Stitch up as small square in peyote or brick (something tightly woven so you will get a definitive front and back result in the sunlight test) of the beads you want to test. Put them in a bowl of water, and liquid dish washing soap, and scrub them around. Compare to unwashed beads of the same color and look to see if the water has changed color. If they have changed, you can stop right there, and know that you will need to seal the beads before using. If they have not, then take them outside and put them somewhere they can be in direct sunlight undisturbed for a couple of days. I taped mine to my porch railing, making sure that the majority of the beads were not covered by the tape. If you find that they have faded, then you need to seal them with something.
What seems to work best for sealing beads is this. Before using them, place in large ziplock and spray with your favorite artist fixative (do not breath the fumes coming back up out of the bag). Seal the bag up and shake vigorously, keep them moving and work them between your fingers so they get evenly coated, and do not stick together. Then use!