PLEASE NOTE: THIS THREAD IS NOT ABOUT WHETHER THE PEN WORKS OR NOT. IT IS AN INFORMATIVE POST FOR FELLOW PEN USERS. I found that my CD pen was starting to get rather thin and transparent, and consequently less effective. Not surprising since I've treated 190-200 or so CDs with it. However, I discovered a not unsurprising method of prolonging its useful life. Simply storing the pen vertically, with the tip at the bottom has got the opaque particley stuff back to the tip, and so it's no longer running transparent. I've redone a few CDs that only got a thin transparent layer before, and it's running pretty much as when new. Obviously it will only stretch so far, but it gets a few more CDs out of it.