In the prototyping phase, I had the stepper motors and their controllers set up on the office desk. In order to see the motors revolving I had attached small flags made of Sellotape to the spindles.
When the time came to remove the Sellotape, it was surprisingly difficult to do, and the use of something to scrape it off made small marks on the spindle with the danger of rendering it slihgtly out of true ... the other option of leaving bits of Sellotape attached would also result in out-of-trueness when coupled to the next shaft.