described herein are pipette tips that include rigid axial projections circumferentially disposed around the exterior surface of a relatively more compliant annular member . the rigid , axial projections may enable improved , and often optimal , sealing engagement with a dispensing device by allowing deformation of the annular member between the projections , and restraining overall deformation of the annular member . pipette tip embodiments described herein readily form a desired seal with a dispensing device , and permit ejection after use without modification to the dispensing device .