Pen To Paper tried out a One Business rollerball with a line width of 0.6mm – the thickest in the range – and found it very pleasant to write with due to a smooth and even ink flow and a rubberised grip for stability and comfort.
We also tested a One Hybrid N rollerball with a needle tip and line width of 0.3mm (a 0.5mm version is available). You might expect a pen with such a fie tip to be scratchy, but, like all of the models in the series, it writes very smoothly.
We tested ink permanence by soaking a sheet of paper with water. The ink didn’t run or smudge even when rubbed. Colours remained bold, though the black ink did yellow slightly at the edges after getting wet.
To demonstrate the special properties of permanent ink, we ran the same test with a general rollerball and found that its ink smudged very easily when wet – clear proof of the benefits of using a permanent rollerball when stability and durability is required.