Rant: I cleaned every lens with the same cloth for 2 years and a scratch on a client's 50mm finally made me stop
I always figured a microfiber cloth was a microfiber cloth, so I kept one in my bench drawer and used it on everything from eyepieces to front elements. Last month a guy brought in a Nikkor 50mm f/1.8 with a hairline scratch right at the center, and when I traced back my steps I realized grit had been trapped in that cloth for who knows how long. How do you all store your cleaning cloths so they don't turn into sandpaper, separate bags, wash after each job, or something else?
That line about grit trapped in the cloth for who knows how long got me, because I did the same thing with a lens pen brush I'd been using for ages. Took a close look at it under a lamp one day and there was a whole colony of dust living down in the bristles.