Objective To realize the function of CIP4 ink key presetting. Methods Visual C + + 6. 0 platform was used to extract the ink key presetting information from the ink zone settings framework of " InkZoneProfile" node in the JDF document root resource pool node " ResourcePool " . According to the structural feature of JDF document, a solution of ignoring minor message and positioning key information was adopted. The relationship of dot area ratio and ink key value was obtained by experiments and a fitting curve was established using least squares. Interpolation method was used to convert the dot area from the JDF document to ink key value. Results Experimental results showed that satisfactory printing product can be obtained after fine adjustment in the ink key value of ink zone obtained by this technique. Conclusion This technique is obviously beneficial for improving the printing capacity.