Chris Lilley wrote: > The L value for the white patch in the color checker should be 95, not 100, > no? (And the 'black' > patch actually has L of around 20). Something like that, but the profile data is relative colorimetric, and the 95% (or whatever) white patch will become PCS 100% white by default. The -u flag allows building a (non standard) absolute colorimetric profile in which the white patch becomes its expected reflectance (ie. 95%). Graeme Gill.