Black Jack - 2NDS - Trautman
Unique! Black Jack goes almost clear when hot, but self-strikes back through brown to near-black depending on how thick you use it. Black Jack likes an oxidizing flame, but does not reduce with gray streaks like most black boro colors.In the curls shown here, we had to get the glass right on top of the light to see the brown where it's thinner.
Black Jack is not suitable for thin stringer work where you want the stringers to look like a dense black, but it's the perfect color for very specific things, like sculpting without the graying. Because this glass goes clear when hot then self-strikes, it is useful in applications where, say, you want to mask a weld.
Second quality glass can have the properties of odd quality glass, but may also have small stones, air bubbles, vary in tone/shade, or the shape can be very out of round. Second quality glass can provide a great value to the right person.