Lead-free and cadmium-free frits

A frit essentially free from cadmium and lead demonstrating good glass stability, a coefficient of thermal expansion (20.degree.-300.degree. C.) between about 52-65.times.10.sup.-7 /.degree.C., a viscosity suitable for firing at about 850.degree.-1100.degree. C., and excellent resistance to attack by acids and bases as evidenced by no visual change in appearance and a weight loss of no more than about 0.05% after an exposure of 24 hours at 96.degree. C. to a stirred aqueous solution containing 10% by weight citric acid and by no visual change in appearance and a weight loss of no more than 0.02% after an exposure of 24 hours at 96.degree. C. to an aqueous solution containing 0.3% by weight alkaline detergent, said frit consisting essentially, expressed in weight percent on the oxide basis as calculated from the batch, of

• ______________________________________ SiO.sub.2 51-60 B.sub.2 O.sub.3 4.5-8 BaO 0-13 SrO 0-18 BaO + SrO 6-30 ZrO.sub.2 4-8 Al.sub.2 O.sub.3 5-8 Li.sub.2 O 0-4 Na.sub.2 O 0-5 K.sub.2 O 0-5 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 1-5 MgO 0-6 CaO 0-12 Bi.sub.2 O.sub.3 0-10 MgO + CaO + Bi.sub.2 O.sub.3 0-20 ______________________________________