Observations on some Commercial Colour‐matching Lamps

Four commercial colour‐matching lamps of the fluorescent‐tube type have been considered. Differences exist between the lamps and Illuminant C, and also lesser differences between the lamps themselves. Samples vary in hue from lamp to lamp, but no serious discrepancies have been found in colour matching: i.e. a match under one lamp is usually a match under one of the others, Since in a large, number of cases the dyeing has been found to have a similar spectral curve to the pattern. Daylight, is very variable, and it is doubtful whether a single standard colour‐matching lamp would he advisable.