Colloids with the shape of a disk or plate are the building block of many natural materials. Our lab has discovered ways to control the size, thickness and polydispersity of discotic colloids. We will talk about the first measurement of the hindrance function for sedimentation or creaming of discotic colloids via the analytical centrifugation. Disks align with the external flow right above a volume fraction of a few percent, and this effect is extremely sensitive to the aspect ratio of disks. Due to this alignment effect, disk sedimentation or creaming demonstrates distinct trends in dilute and semidilute regions.