Abstract Details are given of the properties of cermet resistors produced by evaporation of chromium and silicon monoxide. The resistors have been produced over a range of sheet resistances, between 200 and 4,000 ohms/square. The reproducibility of results decreases with increasing sheet resistance and suggests that 2,500 ohms/ square is the maximum for a practical resistor system. The resistors show extremely good electrical stability, both on and off load, under humid conditions. Noise values are low and temperature coefficients over the whole range of resistivity are in the region of ± 125 p.p.m./°C.