Bests & Worsts Reviews from Amazon

The SL-F1 is not the shortest pen I have, but it may be the most convenient. No clicky-clacky here, just stretch it open, compress it closed. It's even simpler than the True Utility pen, because it doesn't need a cap. The SL-F1 dimensions are published, but my own measurements are: length: 3.318 compressed, 4.231 expanded; barrel diam: 0.320; weight: 11 g. I didn't need the clip so I Dremeled it off (see photo). For me, the best thing about the SL-F1 is the d1 refill. Easy to change, and many makers to choose from. Following are quick and subjective judgments of some refills. Score higher equals better, on: line darkness, smoothness, tendency to skip, tendency to blob: Monteverde 0.7: 2;2;3;2 Monteverde 1.4: 4;3;2;2 (interesting attempt in bold ballpoint ink) Zebra 4C 0.7: 2;2;3;1 (SL-F1 ships with this) Zebra Sharbo X Gel 0.5: 4;1;4;3 (this is the gel alternative, good looking, but runs out fast) Pilot 1.0: 2;3;2;2 (not recommended, dimensionally unfit) Platinum 0.7: 2;2;3;1 Tombow 0.7: 2;2;4;2 Schmidt M: 2;3;4;3 (decent overall performance) Rotring M: 2;2;3;2 Parker M: 2;3;2;3 Cross M: 2;3;3;3 (not recommended, dimensionally unfit) Lamy M21 M: 2;2;3;2 (works, though actually undersized) The easy availability of refills which fit without hacking is a big plus, because there is some voodoo about carrying a ballpoint around in your jeans that makes good refills go bad. Currently I am switching back and forth between pocket pens, but the SL-F1 is definitely a contender. Many vendors, including Amazon's, charge too much for this pen. Become acquainted with its normal retail price before ordering.