Objective To solve the color difference problem between the cigarette packet samples and the proofs of Hongtashan ( Classic 100 ) of a company in Suzhou, the process parameters in the aluminum coating process were adjusted, and the optimal production program was determined. Methods Data was collected from different proofing machines to find out the relationship between the aluminum layer thickness with the corresponding square resistance, and a fitting equation of Rs-d was obtained by analyzing the experimental data and drawing curves. Results The square resistance decreased with the increasing aluminum layer thickness, and the decreasing speed was different within different intervals of aluminum layer thickness, with a demarcation point of (2.61, 2.54). Conclusion Controlling the square resistance of the aluminum layer within 2.21~2.72 Ω could effectively solve the color difference in the proofing process.