Nibs III: Flex vs. Italic

(This page published July 1, 2003)

[ Reference Info Index | Glossopedia ]

Like italic nibs and their oblique-italic siblings, flexible nibs produce line variation. But the mechanisms by which the two work their magic are very different. This article explores how they work and explains the difference in their behavior. On this site, Nibs I: The Basics gives an introduction to nib types, and Nibs II: Beyond the Basics with Specialty Nibs illustrates the differences between flex, italic, stub and oblique italic nibs in handwriting.

The illustration to the left shows the basic parts of a nib’s anatomy.

The Italic Nib

The writing tip of an italic nib is not narrowed to a point or rounded to a round shape as shown in Nibs I: The Basics. Instead, it is cut straight across and thinned top to bottom, as shown here:

This shape causes the italic to make broad up-and-down strokes and narrow sideways strokes, as described in Nibs I: The Basics. The drawback, if there is one, is that the writer cannot control the degree of line variation to any significant extent. For all practical purposes, the strokes are as broad or narrow as the nib makes them. The following illustration shows the line variation produced by a crisp (“chiseled”) italic nib:

The Flex Nib

A flex nib does not produce line variation as a result of its tip shape. Instead, it has an ordinary round tip. Its tines are longer and thinner than those of an ordinary nib, and this design makes them more flexible. The following illustration shows the difference in shape between an ordinary nonflex nib (top) and a flex nib (bottom):

The tines of a flex nib curve upward and spread as pressure is applied during writing; the more pressure applied, the broader the nib slit becomes — up to the nib’s flexibility limit, beyond which point damage occurs; the tines crease upward near the breather hole, and the nib is said to have been “sprung.” The following illustration shows how the flex nib’s tines spread:

Another difference between ordinary nibs and flex nibs, visible in the figure showing the two nibs together, is that the tine tips of a flex nib press gently against each other when the nib is at rest; most nonflex nibs have a very slight space between the tines. The flex nib’s tines, pressing together, allow the writer to start a line and get good capillary action going to draw the ink onto the paper before they spread; this prevents the premature cutoff of the line that would occur if the tips spread too quickly to allow establishment of the ink flow.

The following illustration shows an example of writing with a flex nib; compare it with the italic sample above:

As you can see, there are similarities in the line variation. But there are some pronounced differences, as pointed out in the following figure. (Click a red number in the figure to jump to the description of the difference illustrated by that number.)

This figure illustrates the essential differences between the two nibs’ writing:

Downward vertical strokes remain the same width throughout when written with with the italic nib, while with the flex nib they begin narrow, grow broader as pressure is applied during the stroke, and then tail off, growing thinner as pressure is released toward the end of the stroke. This behavior is impossible to achieve with an italic.
Strokes in a generally upward direction are broad when written with the italic nib because the nib controls the stroke width. But when written with a flex nib, these strokes are usually narrow because it is natural to reduce pressure during upstrokes. (In fact, it is almost mandatory to do so when writing with an extremely flexible extra-fine nib in order to prevent the tine tips from digging into the paper and spattering ink.)
This is another illustration of the varying width of downward vertical strokes written with a flex nib. The two ts in interest show the effect clearly.
The s in interest illustrates a downward stroke in the direction that produces broad strokes when written with an italic. With the flex nib, however, some of these strokes — such as the one in this s — are written with reduced pressure and are therefore narrow. Like the thickening and tailing off of downward vertical strokes, this behavior is impossible to achieve with an italic.
This is another illustration of the contrast between an italic’s broad upward strokes and the narrow strokes of a flex. Once more, the thin strokes shown by the flex are impossible to achieve with an italic.

Semiflex or Superflex?

Having established that there is a difference between flex and italic nibs, let’s now turn our attention briefly to degree of flex.

It turns out that any nib, whether designed as a flex nib or not, will bend to some degree if pressed. A rigid, or manifold, nib won’t bend very much even under hard pressure; it was designed to resist bending so that it could be pressed hard enough to make carbon copies. An ordinary firm nib bends a little, and its tines even separate a bit, but this is not true flex; the nib wasn’t designed to be a proper flex nib. Some modern nibs appear flexy and can give surprising results when pressed, but these nibs really are only springy or bouncy; again, they’re not made to be flex nibs. Much of the increase in line from nibs of this type is just a much wetter line that results from the dramatic increase in flow that occurs as the nib is lifted from the feed.

But even among flex nibs, there are varying degrees of flex. A semiflex nib doesn’t spread as far, under the same amount of pressure, as a more flexible nib. In general, semiflex nibs are easier to use, but of course they don’t give you as marked line variation. The following figure shows my writing with a very fine semiflex nib; the pen I used is an Eversharp Skyline:

With a more flexible nib, I can get much fatter broad strokes with the same amount of effort. The following sample shows the same phrase, written this time with a Pelikan M250 nib that I have modified to be very flexible.

At the extreme end of the flexibility range is the superflexible nib, or “wet noodle.” These nibs, commonly found on vintage pens such as the Mabie Todd Swan, Remex eyedroppers, Moore’s Non-Leakable Safety Pen, and Waterman’s pens such as the relatively common No. 52 (shown here), are capable of laying down strokes with astonishing breadth.

Here is a sample of my writing with a Remex eyedropper. To make this sample, I actually had to “throttle back,” applying less pressure overall; the nib is simply so flexible that I cannot write legibly with it while applying the heavier pressure required by a semiflex nib and tolerated by a flex.

Very few pen manufacturers currently produce models with flex nibs. Most people know about the Namiki Falcon, whose nib is a fairly unresponsive semiflex when compared to a good vintage nib such as you might find in a Waterman’s 52. The best way to get flex on a modern pen is usually to start from scratch and have the nib modified by an expert. The best results are usually obtained with 14K nibs, as most 18K nib alloys are either too soft or too stiff to respond well.

Flex Italics

Believe it or not, there are nibs that combine the glory of flex with the spectacle of italics. But such a configuration can diminish the impact of the nib because the two mechanisms for producing line variation interfere with each other: Vertical or low-pressure strokes that would be thin with a flex nib can't be thin because of the italic tip. The elegant uniformity of stroke that is the hallmark of the italic is marred by the flex, which makes extra-broad strokes under pressure. Some writers love this unique style. Here is an example from a flex italic nib; the pen used is a 1918 Parker Jack-Knife Safety with its original unmodified nib:

In Conclusion

The negative side of any flex nib is that it is more difficult to use than a nib that is not designed to flex, such as most italics. It’s always possible, of course, simply to write with a flex nib and let your normal writing do whatever it will do; but part of the fun of flex nibs, as also the fun of italics, is in seeing how far you can go. But be warned: as I mentioned earlier, it’s possible to push any nib, flex or firm, too far and damage it. So take care, and enjoy!

The information in this article is as accurate as possible, but you should not take it as absolutely authoritative or complete. If you have additions or corrections to this page, please consider sharing them with us to improve the accuracy of our information.