Homogeneity profiles of the constituent films of a single silver layer product were determined using transmission and reflection measurements across the width of the substrate. Measurements were made with a traveling measurement system common to many industrial magnetron lines. The technique, based on Fresnel relations, and using pre-determined dispersion functions for the film materials, provided good correlation between homogeneity profiles using real time online measurements and profiles determined from spectrophotometric laboratory measurements. (c) 2005 Elsevier B.V. All rights reserved.