NS-01 Of the four shades of cobalt blue Northstar produces, this ranks as the second lightest. NS-01 is well suited for small blown work, as well as sculpture when a medium transparent blue is desired. NS-01 Cobalt Blue can take a lot of heat and can be worked in a wide range of flame settings. Though the color is extremely intense, be sure to stay out of reducing flames to prevent any dulling or graying. For additional information about working NS-01 Cobalt Blue or other cobalt blues refer to Northstar Newsletter issue 16.