Ensso Puma Pocket Ultem Review: A Pocket Pen That Grows to Full Size

Introduction

The Ensso Puma Pocket is a small fountain pen with a simple trick: unscrew the generously sized cap, screw it onto the back of the barrel, and you have a full-size pen. This version is made from Ultem, a high-strength engineering plastic with strong chemical resistance, used in demanding applications including jet engines. It is translucent, rigid, and gives the pen a distinctly robust feel. The pocket model has appeared in other materials before, but Ultem changes the character of the pen enough to justify a fresh look.

The Puma Pocket in Ultem is priced at 95 USD and comes with a choice of three number six nibs: a mirror-finish stainless steel nib in fine, medium, and broad, a black-coated stainless steel nib in fine and medium, and a fine titanium nib.

Who This Pen Is For

This is a pen for people who want genuine pocketability without sacrificing a proper writing experience. Unposted, it is a genuinely tiny pen that some writers can use directly, though many will find it too small for comfortable use. Posted, it becomes a full-length pen with no wasted space, which is the entire design principle behind the Puma Pocket.

If you went through a pocket pen phase, or you commute with a jacket pocket or a small bag, the posted format makes a lot of sense. If you prefer larger pens and never carry one loose, the appeal is narrower.

Main Strengths

The Ultem material is the headline feature. It feels very rigid and solid in the hand, with a certain robustness that is immediately noticeable when handling the cap. The translucency is genuinely useful too: you can see the ink level in a standard international cartridge through the material, and in eyedropper mode you get a clear view of how much ink remains.

The pen ships cartridge-filled with a standard international cartridge, and it can also be converted to eyedropper filling. That matters for a small pen, since standard international cartridges do not hold much ink. There is an O-ring in place, and Ensso notes that the threads are designed to repel ink, though the company recommends adding a little silicone grease to the nib unit threads before converting. If you do eyedropper-fill, keep in mind that an accidental unscrew means a lot of ink where it should not be.

The nib unit is an unbranded number six Bock nib with a fine ABS feed. The fine steel nib writes with a little feedback but is not scratchy or unpleasant. The black-coated option has coated tipping, which produces its own slightly less smooth feedback, and the coating on the tipping will wear off over time from paper contact, after which it tends to write smoother. It is not a wet writer, and it is not a flex nib, though careful pressure produces a small amount of line variation. Reverse writing is not its strength; the nib dries out quickly.

Things to Consider Before Buying

The main consideration is price. At 95 USD for a fairly small pen with a steel nib, this is not cheap. That said, the pen feels well built, the material is a genuinely interesting and robust choice, and the design works well as a whole.

The other consideration is filling. You get a standard international cartridge in the box, and that is it. Some small converters, such as mini piston converters or squeeze-type converters, may also fit, but capacity is limited unless you commit to eyedropper mode, which carries a small leakage risk if you are the cautious type.

Buying Advice

If you like pocket pens, the Puma Pocket in Ultem is one of the more interesting options around. The posted size makes it practical for everyday carry, the translucent barrel solves the ink-level problem elegantly, and the nib options give you room to pick a writing character you enjoy. Compared side by side with a standard full-size pen, the difference in unposted size is dramatic, and that is exactly the point.

Choose the mirror-finish stainless steel nib if you want the smoothest conventional experience, the black-coated nib if you prefer a darker look and accept the evolving feedback, or the fine titanium nib if you want the most distinctive option. For anyone wary of eyedroppers, using cartridges is a perfectly sensible default; the translucent barrel keeps the ink level visible either way.

Conclusion

The Ensso Puma Pocket in Ultem is a fun, solidly built pocket pen with a genuinely interesting material, a useful posted full-size format, and flexible filling. The 95 USD price is the main hurdle, but the build quality, the translucency, and the eyedropper capability make it a considered purchase for pocket pen fans rather than an impulse buy. If the format appeals to you, it is easy to recommend.