Various sensor tapes can improve securing of a non-invasive optical sensor to a surface of a medium for taking noninvasive measurement of characteristics of the medium. The sensor tape can taper from a wide end to a narrow end. The sensor tape can transition from a wide portion to a narrow portion in a step-like change or slope. The sensor tape can have staggered portions. The various tapes can be used with an L-shaped sensor. The various tapes can increase contact surface between the surface of the medium and an adhesive side of the tape so as to reduce motion-induced noise.