Narwhal Original Plus Rainbow Ras vs TWSBI Vac 700R Iris: Two Rainbow Vacuum Fillers Compared

Introduction

Rainbow pens tend to be either charming gimmicks or genuinely well-made instruments. Every so often, one manages to be both. The Narwhal Original Plus Rainbow Ras is a Goldspot Pens exclusive that arrives wrapped in protective film, and the first impression is immediate: this is a glitter rainbow acrylic pen with rainbow trim and a full rainbow-plated nib, and it is far sleeker than you might expect.

That sleekness is exactly why it invites comparison with the TWSBI Vac 700R Iris, a long-standing favorite in the vacuum-filler category. Both pens are vacuum fillers with transparent personalities, similar sizing, and playful translucent finishes. But they also differ in some important ways, starting with the TWSBI’s distinctive center bulge and ending with where the nibs come from. Here is a closer look at how the two compare.

Narwhal Original Plus Rainbow Ras: Design and Build

Out of the box, the Narwhal is genuinely striking. The acrylic resin carries a constellation of glitter and iridescence that shifts as the light moves, and it almost looks like a shimmer ink is already loaded inside. The rainbow treatment extends everywhere: the trim rings, the cap, and, most exciting of all, the nib itself. A full rainbow nib is a rare treat, and it earns the pen’s name honestly.

The form factor is where this pen pulls ahead of its rival. It is slimmer and lighter than the TWSBI Vac 700R, with a clean taper-free silhouette that calls to mind the venerable Pilot Custom 823 in its dimensions and overall elegance. There is no awkward bulge in the middle of the barrel, no strange taper in an odd spot. Fit and finish feel very much equal to the TWSBI, and the filling mechanism worked smoothly on the very first attempt. At $65, with an in-house nib included, that is more than fair.

TWSBI Vac 700R Iris: A Beloved Pen With One Flaw

The TWSBI Vac 700R Iris remains an extraordinary pen. The iris-colored demonstrator resin is lovely, the vacuum filler is proven and reliable, and the writing experience is well established. The pen is a touch longer than the Narwhal, which some hands will prefer.

The persistent complaint is architectural: the inelegant bump at the center of the barrel gives the pen a slightly strange taper in an odd place. It is a small thing, but next to the Narwhal’s sleek lines it stands out. The nib is supplied by JoWo rather than made in-house, and while it carries a rainbow treatment in the right places, it is not a full rainbow effect. The Iris version typically lands somewhere around $80 to $85 US, notably above the Narwhal’s price.

How They Fill: Vacuum Mechanisms

Both pens are vacuum fillers, which means you unscrew the back, pull the piston up, and press it down to draw ink into the barrel through vacuum action. It is a satisfying, dramatic fill, and the Narwhal’s mechanism produced a solid fill on the first try with a smooth, confident stroke.

There is not much separating the two mechanisms in day-to-day use; both deliver generous ink capacity and the ritual fountain pen owners know well: a careful nib wipe, a clean section, and a moment of patience before the first stroke.

Nibs: In-House Steel vs JoWo

This is the quiet story of the comparison. The Narwhal uses a number 6 steel medium nib made entirely in-house, with full rainbow plating. An in-house nib at this price is genuinely uncommon; only a handful of manufacturers, Pilot, Lamy, and Platinum among them, take on that cost at this level. The nib turned out to be a pleasant surprise: it is one of those thinly cut mediums, very smooth, very precise, with abundant ink flow that never feels sloppy or wet. No false starts, no skips, and enough discipline to keep up with fast writing.

The TWSBI’s JoWo nib is a known quantity: dependable and pleasant, with rainbow accents but not the full rainbow treatment of the Narwhal.

Writing Experience

The Narwhal earns high marks where it matters most, on paper. On a Claremont-style reporter notebook, the medium nib wrote with real alacrity, keeping up with the speed of thought without losing momentum or ink. It feels very good in the hand, easy to hold and easy to steer, with dimensions that sit near the sweet spot for most users.

The deep indigo ink test was telling. With no shimmer, no sheen, and no glitter in the ink, the pen’s own acrylic did the sparkling, and the clean indigo strokes looked beautiful against the rainbow resin. As a bonus, the glitter resin is so convincing that you barely feel the temptation to load a shimmer ink, although it would certainly match.

Buying Advice: Which One Should You Pick?

This is a tougher decision than the price gap suggests, but the Narwhal has a few genuine advantages: the sleeker silhouette without the center bulge, the smooth and trouble-free vacuum fill, equal fit and finish, the in-house rainbow nib, and the lower $65 price. Supporting a brand brave enough to make its own nibs at this level is a real reason in itself.

The TWSBI still makes sense if you prefer its slightly longer length or already love its iris demonstrator look. But for pure fun, and fountain pens should be about fun, the Narwhal Original Plus Rainbow Ras is the more inspiring instrument.

Conclusion

The Narwhal Original Plus Rainbow Ras proves that a glitter rainbow pen can also be a serious writer: sleek, light, precise, and filled through a vacuum mechanism that works beautifully. Against the TWSBI Vac 700R Iris, it wins on elegance, nib provenance, and price, while the TWSBI holds its ground as a trusted classic. If you have been tempted by a rainbow pen that does more than look pretty, this Goldspot exclusive makes a strong case.