What differentiates the "rollerball" refill from the "ballpoint refill" is the fact that the "rollerball" refill is based on a water-based liquid or gelled ink. The "ballpoint refill" is based on an oil-based viscous ink.
Due to the fact that the "rollerball refill" is water-based or gelled ink based, these inks tend to saturate more deeply and widely, hence its characteristics that may be advantages for your writing or, perhaps, not.
ADVANTAGES:
[1] Less pressure needs to be applied to the pen to have it write cleanly; less pressure,less stress on the hand.
[2] Due to the wider choice of suitable water-soluble dyes, or to the use of pigments. the inks are more brightly colored and varied.
DISADVANTAGES:
[1] The ink is more liable to smudge as the water-based ink dries more slowly than ballpoint ink.
[2] Being water-based, the ink may penetrate through the paper. Thicker paper may have to be used.
[3] Gel inks do not flow as readily as a liquid ink; this may cause the ink to randomly "skip'.
[4] Both the gel and liquid water-based rollerball inks are dispensed more quickly. You will find that, therefore, you go through more refills compared to using a ballpoint ink refill.
[5] The rollerball pen left uncapped in a shirt pocket or the like is likely to leak.

Technology has allowed an update on the old "felt tip" pen....the fineliner! A fineliner consists of a very firm tip and will remain both strong and sharp over time. This, however, is NOT the refill for you if you have the habit of crushing the tip of your pen against the paper! A fineliner's inks are quick to dry and present little or no friction to lay ink to paper. Usually may be found, also, in finer tip sizes that many rollerball ink refills.

Should you have a question about a particular rollerball/fibre tip refill please fee free to email me at passion4pensinfo@yahoo.com or info@passion4pens.com. Will be happy to field any questions about pen and refill compatibility as best I can.

Please note that each manufacturer has their own version of what is a "fine", "medium" or "broad" tip. Look at the ink line width, if given, as the best marker. As an example, Schneider� Topball 850 05 is listed as a "medium" tip, yet the ink line width is 0.5 mm. This is in comparison to Schmidt� 888 "fine" tip with a line width of 0.6 mm. You tell me which one is the "finer" of the widths. So, look carefully at the information given when you choose a tip size or width.

As it is impossible to have each and every item on hand for every manufacture for immediate delivery, please allow 2-3 weeks from order date to anticipated delivery time. If you have any questions, please contact info@passion4pens.com BEFORE you order to discuss any questions or concerns. Items available for same day processing and next day shipping are so noted. 

Any questions or concerns? Email us at passion4pensinfo@yahoo.com or call at 1-708-337-0472 [please call between 9AM and 5PM CST].