Classic Crackles add a level of sophistication and dimension to your designs. The cracked effect has traditionally been used to create a vintage or antique appeal. Increase complexity by using in combination with other glazes or design work. Classic Crackles are non-toxic, low fire (cone 06) glazes that are designed to "craze"; that is, develop subtle surface cracks in the finished glaze. This cracked effect has traditionally been used on home decor pieces by designers looking to create a vintage or antiqued appeal to their pottery. General Use - Classic Crackles are non-toxic, low fire glazes designed to create crackle patterns during the firing process. Perfect for home d_cor pieces. To highlight the cracks, after firing wipe an acrylic or ink over the ware and wipe off, allowing the ink to fill the cracks.