Abstract: To improve tightness of a pinch or press seal (2a; 13a, 13b) between a modenum foil and quartz or similar hard glass of an electric lamp, typically a halogen incandescent lamp or metal halide discharge lamp, an intermediate melt glass layer in form of a strip is applied to the sealing foil, which has the following main components:SiO.sub.2 : 60-70%Al.sub.2 O.sub.3 : 3-20%K.sub.2 O: 12-18,all percentages by weight, the glass being, except for trace contaminants, free from Na.sub.2 O. In a preferred form, the main components are:SiO.sub.2 : 66%Al.sub.2 O.sub.3 : 18% K.sub.2 O: 15%,all percentages by weight.