Vetrofond glass double helix . 104 dichroic coe. strips sheets assortment. 104 frit. effetre frit : boro color tube & rod. glass alchemy trautman art glass northstar golden gate tubes. boro clear tube & rod. simax glass rod simax glass tubes : boro 33 coe frit. glass alchemy frit northstar frit Northstar glassworks is a small business that lives on experimentation, innovation and through the dedicated artists that use their products. continuous development and working additions have transformed northstar glassworks into the premier borosilicate color glass manufacture. Mar 02, 2015u00a0u00b7 the word u201cfritu201d is italian in origin and refers to ceramic mixtures that have been melted to form a glass and then crushed into a powder. glass frit is a type of pre-reacted raw material that can be used as-is or combined with other materials in a custom blend. these frits are used in making such diverse products as decorating enamels, sanitaryware, refractories, u2026 Fritted discs are made by heating glass particles or fibers at a high enough temperature that they fuse together sufficiently that they become a relatively strong object. in our case, the glass is borosilicate glass, and is the same as the standard material for laboratory apparatus, i.e. pyrex 7740, kimax kg-33, or schott duran.