I bought the Uni-ball Signo UM-153 Blue-Black with a 1.0 mm to see how much thicker it was to the UM-100 with a 0.5 mm tip. It is very inky and it lays down a thick line, too thick for my writing style: my “a”, “e” and “o”s end up looking like “i”s. It’s fun to doodle with it and the pen runs very smoothly, but, for me, it’s not practical for normal writing. Because it releases a lot of ink, I have a feeling it won’t last long. Also, the blue-black leans green, and I prefer red leaning blue-blacks such as Pentel EnerGel RTX Navy Blue and Zebra Sarasa Clip Gel Blue-Black.
