Franklin-Christoph S.I.G. Flex Nib Review


I’ve had my Franklin-Christoph S.I.G. Flex Nib in regular use for a couple of months now, and I find two statements to be true about it’s performance:

  • It is an awesome feeling nib.
  • There is little line variation.

When I have talked about this nib in other places I keep saying it is not a flex nib. That’s not exactly true. It does flex in the literal sense, as in the tines spread and the nib bends, but it does not provide what I consider to be flex nib output, meaning noticeable line variation when pushed. Not with light pressure, not with heavy pressure. But that doesn’t keep this nib from being great in my book.


What this nib provides is bounce, not flex. You can push the nib and watch the tines spread. It is a fantastic feel, and a great writing experience. Just don’t expect much line variation. My fine S.I.G. grind goes from a medium width line to a mediumer line. And I’m ok with that because my line looks great and the nib feels great.

S.I.G. stands for Stub Italic Gradient, which is a nib grind done by F-C’s in house nib meister Jim Rouse. It is perfect for someone like me who enjoys a cursive italic grind but without the sharp edges is often comes with. This grind smooths those edges out while keeping the horizontal and vertical line variation that I enjoy so much.


To achieve flex in this nib, Jowo (the nib manufacturer) added cutouts above the shoulders of the nib. In theory, this allows the tip to be pushed when writing for added flex. The output just isn’t as impressive as the look. Nib meisters have added cutouts and slits to nibs for years to provide added flex. Jowo, and other nib manufacturers, are now adding this feature as a stock offering, which is a good sign that they are listening to us consumers. Just don’t be confused about what you are actually purchasing.

If you are looking for line variation as found with a traditional flex nib, this is not the nib for you. If you are looking for a wonderful writing nib with a ton of character and fun, then check out the S.I.G. flex nib. I’m completely enamored with mine and enjoy using it. I may even add a second one to the lineup one day.

(This nib was purchased at full price with my own funds.)

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Posted on September 11, 2017 and filed under Franklin-Christoph, Fountain Pens, Nibs, Pen Reviews.