Periwinkle 

Periwinkle is a fully opaque baby blue that is great for blown work and stringer application. To prevent any boiling issues heat Periwinkle slowly and gently. Once the color is glowing it can take a lot of heat. The trick is patience with a soft flame! Periwinkle is sensitive to atmosphere, and must be worked in a soft neutral to oxidizing flame. Try layering Light Cobalt over Periwinkle for bright neon blue. Also, be sure to try layering Irrid over Periwinkle.

Available in Rod, Frit, Fine Frit, and Powder.

Northstar Glassworks Borocolour Colored Rods & Frit

Northstar Borocolour has a COE of 33 and may be combined with Simax, Northstar and any other glass with a similar coefficient of thermal expansion.

Northstar Glassworks Borocolour Colored Rods are an average length of 18" with a diameter of 5-9 mm diameters. Hand pulled tubes vary in length from 8-22 in. with a diameter of 15-38 mm and wall thickness range of 2-6 mm.  Northstar Rods and Tubes are sold by the pound with a 1/4 pound minimum purchase per color.

Northstar Borocolour frits are available in five grain sizes. Large frit is coarse 25 mesh - approximately .055 inches or 1.397 mm. Small frit is finer 38 mesh - approximately .024 inches or .6096 mm. Fine frit is 70 mesh and and powder is 100 mesh. These four frits come packaged in 4 oz. containers. Some colors are available in 16 oz. The fifth product size - called fore powder is between fine and powder in grit size and comes in a 16 oz. container.