The recently emerging interest in fibrillar biological attachment systems, as those found in the gecko, has led to the fabrication of micropatterned elastomer adhesion surfaces. Reported studies have demonstrated that measurements on micropatterned surfaces are affected by experimental parameters not relevant for flat samples. The present paper investigates the influence on adhesion values of the sample stiffness, the backing layer thickness, the ambient humidity, and of repetitive measurements at the same location. Measurements were performed on PDMS (Sylgard (R) 184) micropatterned surfaces possessing flat-ended pillars with 10 mu m diameter and 10 mu m height. We find that adhesion increased with decreasing sample stiffness and decreasing backing layer thickness, whereas it dropped when several tests were carried out at exactly the same location. For ambient humidities between 2 and 90%, no influence on adhesion performance was found.