Thursday, June 18, 2015

Bead Kiln @ Artisans' Village (playing with stringer part 1)

At Artisan's Village I had a chance to try decorating a bead with zig-zags. This is a perfectly period bead design, and a green and yellow version of this bead can be found on my most recent Anglo-Saxon Necklace project (look to the top right of the necklace). Just like the last time I worked with the kiln, I used 120 COE glass.

The decoration technique I was trying to reproduce was one I saw in this video from Artisans d'Historie (a reenactment group in France).

 I used a pontil to gather the yellow glass I wanted to decorate my transparent dark blue base bead with. This glass had been melted in a small iron crucible. In period they might have softened glass on iron pan placed by the site of the fire, or melted glass in ceramic crucibles placed in the kiln (as seemed to be the case in the video). Once I had my glass gathered onto my pontil, I then touched the yellow glass to the blue bead, pulled back slightly, drew the glass to the other side of the bead and slightly forward, and touched down again.I repeated this pattern around the circumference of the bead.

It worked reasonably well. The yellow glass stayed soft enough for me to do this in the open fireplace I'm not sure 104 coe glass would have worked as well, but I have not tried that yet.  The only issue was that I didn't melt the decoration in all way before cooling the bead. I don't think I realized how raised the decoration still was until the bead cooled down.


One of my sources, archeologists Tine Gam, has done some experimental archeology herself, and she proposes a slightly different method. I will have to try this method out the next time I make beads. Gam thinks that the beads were made by drawing out a thread of glass from the pontil using tweasers, breaking off the tweaser marks (creating glass waste) and then melting the thread onto the bead. Moving the bead back and forth  would help create the zig-zag pattern. The image below is from the article by Gam.

However, Gam notes that the color of the waste glass with tweezer marks found at Ribe does not perfectly match  the colors used to decorate beads at Ribe. Instead, much of the glass waste with tweaser marks matches the colors of the base beads. Perhaps this means that the method used by the Artisan's d'Historie reinactors could be correct? Or, maybe more than one method was used?  I actually think this may be likely, simply because I know that in crafts there is often more than one way to do something. For example, there are at least three different ways in modern lampworking to make twisted glass canes.

Finally, Gam also notes that a small metal tool could be used to improve the zig-zag shape. After the lines have been placed, the glass designs can be moved slightly while it is soft. This is something I already do when making beads on my torch!  Gam notes evidence of this from Ribe, including a narrower shape to the corners of the zig-zags on some beads, and small air bubbles in the beads (as seen under a microscope)  that follow the direction the glass would have been pulled by the metal tool. I always thought I was fussing a bit to much when I tried to correct the shape of my decoration in this way, so it is good to know that this was done in period!

Gam, Tine. (1990). Prehistoric Glass Technology: Experiments and Analysis. Journal of Danish Archeology, 9.p. 203-213.