Lightly tacks glass pieces in place prior to firing. Slow drying and pliability allow readjustments as you work. Organic colorant lets you see where you've put it on clear glass but it burns out in the kiln. Use sparingly. Water soluble. A 32 fl oz (.95 L) bottle of GlasTac. For refilling the 4 oz applicator bottle.br> This product is manufactured by Bullseye. Slumpy's proudly manufactures and distributes a variety of products. For the most up to date product information, vendor news, and best practices, click here.