Along with the uni-ball Air, the Signo 307 is one of more recent offerings by uni-ball to hit store shelves in the U.S., and if we’re to take its name at face value, it seems to be an upgrade to uni-ball’s popular Signo 207 pen. Of course, it just so happens that the Signo 207 is one of the best gel pens on the market and one that I end up recommending quite frequently. So if uni-ball has somehow managed to make it better, then that would be quite an accomplishment.

The main difference between the Signo 207 and the Signo 307 is their refill – the 207 uses the UMR-87 refill, and the 307 uses a refill labeled “UMR-87E,” both of which are quite good. The 307’s ink is a little smoother and bolder, but the 207’s ink seems to smear less. The 3o7’s main selling point, however, is that it writes better glossy paper, and for a gel pen, it does a surprisingly good job of this. But if writing on glossy paper is a major concern for you, then you’ll still be a lot better off with a pressurized ballpoint pen.

In terms of aesthetics, the Signo 307 is undoubtedly cheaper than its predecessor. While I like the 307’s all-black, stealth style, I still prefer the Signo 207 for its professional look and low-smear ink. It should also be noted that the 307 currently only comes in a 0.7mm tip, and UMR-87E replacement refills cannot be purchased separately. So if you want a smaller tip size or intend to refill the ink, you’ll be stuck using a 207 refill anyway.

Extra Links

• On uni-ball’s website, they show that the Signo 307 is available with a 0.5mm tip. I’ve looked high and low, and I haven’t been able to find that size available for purchase. Maybe its coming soon.
• A review at the Penman Post shows some close-ups of the 307’s barrel, which actually has a carbon-mesh design (though he says it chips off easily). He prefers the 307’s refill to the 207, and says that it works well inside a Retro 51.
• Check out the review at That One Pen for lots of good comparison shots between the 307 and 207 (and more).