I have been using the signo unibal for years. I tried other pens and was not satisfied with the intensity of the white. This pen works great all the time if you store it vertically, pen nib down and use it often! I use mine at least once a week and never have problems with it clogging or drying up. If you use it rarely, then you will have bad luck. But, I have used a baby wipe to clean the tip and get it flowing again.