We introduce PolarVisor, where we imprint mmWave fiducial markers with paper and foils. Its key insight is manipulating signal polarization to enable clutter-free detection on its markers. Meanwhile, it builds on recent advances in passive metasurfaces where metallic patterns are readily hot-stamped on paper with foils. PolarVisor adopts an innovative design where the radar wears a visor (also paper-based) to eliminate clutter, leaving the markers readily visible. We include an in-depth analysis of its design and fabrication and we show that: (1) PolarVisor can support clutter-free detection at up to 25 m. (2) PolarVisor reports a self-localization accuracy of 0.0297 m (mean) and 0.0232 m (median) across multiple real-world, multipath-rich indoor environments.