Pilot Parallel Pen, Original Sizes Set

I feel like these pens get a lot more credit than they're actually worth. Are they good? Yes. Will you get clean crisp lines? Absolutely. Some of the crispest. And you can write with the thin side and the corners, which is a big perk for me. There are just so many things that annoy me about them though, that I can't seem to fall in love with them, or honestly even recommend them. For starters, the pens cannot reuse cartridges or take custom colors of ink (I've found some videos online of how to do this with a syringe, but it's not recommended or supported by Pilot). This means that every color change requires a brand new cartridge (old ones need to be thrown away). I usually change colors pretty frequently, so I quickly realized these might not be the pens for me. They also have screw-top lids, which is a good idea given the construction of the pen, but also more cumbersome than I'd like when I go to change sizes. I prefer a little more grab and go, especially if I'm in the zone and have a good idea on hand, though it does make them more portable, which is nice. Lastly, the ink these pens use seems really identical to ballpoint pen ink. It's thick and sticky, compared to drippy and free-flowing like other calligraphy inks I've used (Dr. Ph Martin's Bombay inks), but it doesn't seem to sit well on most of the practice paper I have around (even though it's thicker stuff that takes watercolor well). It seems like these require a bit more of a specific substrate. I've had pretty good success on vellum, but nothing else I have readily available. I'm glad I tried these pens so I could see what all the hype was about, but I'm not crazy about them and don't know that I'd buy them again, should I ever need to.