The authors have developed a multi-spectral scanner for accurately printing proofs that employs an LED array coupled with a photodiode array to measure the reflectance spectra. The system is composed of an LED array with five different spectral radiant distributions and 2048 silicon photodiodes with a Selfoc lens array (SLA) for imaging. Five types of LED were selected from among 40 types of commercially available LED with different spectral radiant distributions in order to minimize the average color difference ΔE*₉₄ between the measured and estimated reflectance spectra of 81 typical color charts. The multiple regression method based on the clustering and polynomial regression algorithm was introduced for highly accurate estimation of the spectral reflectance for printing. The results indicate that the average and maximum color differences ΔE*₉₄ between the measured and estimated reflectance spectra of 928 color charts were 1.02 and 2.84, respectively. The scanner can measure the reflectance of prints having a 0.5 mm pitch resolution and a scanning speed of 100 mm/s. The field programmable gate array (FPGA) and digital signal processor (DSP) were introduced in order to accelerate the calculation of sensor calibration and the estimation of the reflectance spectra of the printed proof for practical and commercial use. As a result, the developed scanner could measure the reflectance spectra of the printed proof within 20 s.