In this study, a thorough investigation of a pressure-free vertical cloth ironing process on cotton fabric was conducted for the first time, using the data from a sensory evaluation and the test results on a custom-built platform. The importance of such process factors as temperature, steam amount, cooling wind and ironing time are examined, so as to fit them into an empirical equation. Verification of the fitted equation is then conducted by comparing the sensory and predicted data. Finally, explanations and analysis are provided focusing on the physical mechanisms involved to probe the wrinkle recovery phenomenon during the fabric ironing process.