Patent ID: 7551317

Claim:
A method for controlling color in a printing press using at least one ink-feeding device, comprising the steps of: determining spectral reflectance values by taking measurements on at least one printed surface element on a print substrate; converting the spectral reflectance values into corrected spectral reflectance values; determining actual values for ink-feeding variables as a function of the corrected spectral reflectance values; and providing control data for the ink-feeding device as a function of the actual values obtained for the ink-feeding variables and setpoint values for the ink-feeding variables; wherein the corrected spectral reflectance value is determined based on the relation β′(λ)=exp{1n[β(λ)/P unpol (λ)−β 0 ]s}P pol (λ){1−q[P unpol (λ max )−β(λ max )]}V(λ) Dr , D=−log [β/β pap ] with β=∫dλβ(λ)F(λ) and β pap =∫dλβ pap (λ)S(λ)F(λ) being for the spectral reflectance values β pap (λ) of the print substrate.