It causes serious problem because it is not easy to clean the pen clogged with the ink and dried up. Comparing to the ink water-based with dyes, it tends to be stopped up because particles are coarse. If you use your fountain pen with the carbon ink everyday, there may not come problems but in case you have long period to use the fountain pen, it will be clogged. If you do not use the fountain pen in carbon ink for more than one week, please pull out the ink and wash the ink converter thoroughly. We recommend this carbon ink especially to the heavy users who love to write and write. The more you write, the better its performance will be.

Platinum Carbon Ink Bottle - Cult Pens Platinum Carbon Ink Bottle - Cult Pens

The following is copied directly from Platinum and contains important information about using this ink. That is why the carbon ink is suitable for important documents such as official documents which need to be stored for a long time. Some people use the carbon ink to draw a rough design for a picture painted in watercolors or colored inks because carbon ink is run-proof. Platinum's famous permanent waterproof ink. Platinum Carbon Ink is pigmented ink suitable for fountain pens - for documents, drawings (including line and wash) and general-purpose use. However, this ink does have the potential to damage pens if not used according to instructions. This ink can dry and clog fountain pen feeds if left too long as it contains ultra-fine carbon particles. It is only suitable for pens that are in daily use and if the pen is to be left more than a couple of days without use then we advise flushing the pen and converter.