To prevent tights from running, do this little trick before wearing them the first time. Wet the hose, wring them out and place in a plastic bag. Freeze overnight and thaw before wearing. This process mimics cryogenic stress relief, in which an item is frozen to make its molecules stop moving. When the tights thaw, the molecules will be put in motion again, rearranging themselves in a tighter fashion that makes the material stronger and more resistant to wear and tear.