Does Size Make A Difference?

While browsing through a local Office Depot the other day I happened to see some Faber-Castell PITT Artist Pens. My eye fell upon the words on one of the packages: "Superfine Nib". Well that's all it took (for me to ask my lovely wife if I could spend the $2.00 asking price). Even before I got home I had the pen out of it's blister pack and was trying it out. It looked "Superfine" in the car but once I arrive home I immediately began to compare it to my other technical and non-technical porous point pens. That's when I discovered that "Superfine" wasn't as fine as I'd thought.

I was curious as to the actual line width of the pen so I hauled out all my other technical pens along with a few other porous point pens and started to do write with them all in an effort to determine the actual line width of the Faber Castell PITT. I was able to find out that it laid down a line similar to the Alvin TechLiner #03, The Sakura Pigma Micron #03, and the Pilot DR #03. The problem is the Alvin claims it makes a 0.3mm line, the Sakura claims it makes a 0.35mm line and the Pilot claims no line width at all. So which is it? Or am I splitting hairs? No matter. I drug out my trusty dial calipers and did some measuring.

I measured the diameter of the plastic coated fibrous tip in an effort to see what the relationship between shaft diameter and line width was. My results were surprising to say the least. It seems that in the world of porous point pens size is relative!

I measured 17 different pens and the
results are posted below. The pens tested were the Sakura Pigma Micron (SPM), the Pilot DR Drawing Pen (PDR), the Mitsubishi unipin Fine Line (MUP), the Kuretake Zig Millennium (KZM), the Alvin TechLiner Technical Drawing Pen (ATL), the Faber Castell PITT Artist Pen (FCP), the Saford Sharpie Pen (SSP), the Pilot V Razor (PVR) and the Sanford Liquid Expresso (SLE). Other abbreviations used, Line Width (LW), Tip Diameter (TD), Not Given (NG), Superfine (SF), Fine (F) and Extra Fine, (EF).


SPM #005, LW = 0.20mm, TD = 0.33mm. PDR #005, LW = NG, TD = 0.33mm. MUP #005, LW = NG, TD = 0.43mm. SPM #01, LW = 0.25mm, TD = 0.57mm. PDR #01, LW = NG, TD = 0.48mm. KZM #01, LW = NG, TD = 0.53mm. ATL #01, LW = 0.1mm, TD = 0.53mm. SPM #02, LW = 0.30mm, TD = 0.71mm. PDR #02, LW = NG, TD = 0.61mm. ATL #02, LW = 0.20mm, TD = 0.64mm. SPM #03, LW = 0.35mm, TD = 0.79mm. PDR #03, LW = NG, TD = 0.79mm. ATL #03, LW = 0.30mm, TD = 0.79mm. FCP SF, LW = NG, TD = 0.76mm. SSP F, LW = NG, TD = 0.79mm. PVR EF, LW = NG, TD = 0.76mm. SLE EF, LW = NG, TD = 0.76mm.

It appears that there is not much of a correlation between tip diameter and the size of the line the tip makes except that in general the greater the tip diameter the wider the line. With the notable exceptions of the #03 technical pens and the two Extra Fine non-technical pens none of the groups with the same reported size have the same tip diameter. The unipin, which has the finest line of the #005 pens has the largest diameter tip! In the #01 and #02 pens the Microns seem to have the largest diameter tip but lay down a line at least as equal in width as the others, if not finer.

As for the non-technical pens the Razor and the Expresso seem to make the same width line, while the Sharpie makes a slightly finer line. Yet the Sharpie has the larger diameter tip. There just doesn't seem to be any rhyme or reason to the size of the tip and the width of the line, at least in general. But tip width is only part of the story. It's the shape of the end of the tip that has a lot to do with the line width.

Two pens the same designated size can be and often are of different tip diameters yet they lay down the same width line, as we've seen. The reason for this is that the nose of the smaller diameter tip is blunter than the larger diameter tip, yet they booth have the same size opening in the plastic sheath that allows them to have the same line width. The advantage one design has over the other is debatable. One could argue that the larger diameter tip affords the tip greater strength yet the shaper nose is more easily crushed while the nose of the smaller diameter tip may be more crush resistant the smaller diameter tip is weaker over all. But in the long run, does it really matter? It might, as seen under the eye loupe some of the tips were considerably shorter than the others. This also has a factor in the over all strength of the tips.

So, does it really matter to you, the end user, if the tip on your porous point pen is larger in diameter than another of the same size? Or shorter? As long as they lay down the same width line then it shouldn't. But without a greater standardization of size designations I am afraid that we will be faced with slight variations in line width among the same size designation of pens for some time to come.