An indirect media flatness measurement system, and method, by which the appropriate level of hold-down force may be determined with some degree of quantitative accuracy. In an ink jet printer that is operative to subject a substrate media to a hold down force during printing, the method including printing a predetermined test image having a predetermined pattern on a substrate media using an ink jet print apparatus to produce a test print. Optionally, pattern may be an array of test symbols. The test symbol may include a line printed on the substrate media in a direction perpendicular to a process direction of the printer. The test print is compared with the predetermined test image, including measuring drop placement errors of test symbols. The height of the substrate media at the location of each test symbol is calculated based upon the drop placement error.