We propose integrating an array of skin stretch modules with an head-mounted display (HMD) to provide two-dimensional skin stretch feedback on the user's face. Skin stretch has been found effective to induce the perception of force (e.g. weight or inertia) and to enable directional haptic cues. However, its potential as an HMD output for virtual reality (VR) remains to be exploited. Our explorative study firstly investigated the design of shear tactors. Based on our results, Masque has been implemented as an HMD prototype actuating six shear tactors positioned on the HMD's face interface. A comfort study was conducted to ensure that skin stretches generated by Masque are acceptable to all participants. The following two perception-based studies examined the minimum changes in skin stretch distance and stretch angles that are detectable by participants. The results help us to design haptic profiles as well as our prototype applications. Finally, the user evaluation indicates that participants welcomed Masque and regarded skin stretch feedback as a worthwhile addition to HMD output.