Hey guys! Normally post in the Japan pens forum but I picked up a TWSBI 580ALR from Mark Bacas with a special nib grind and I wanted to share some info about it.
First off - the ALR is just like an AL except the cap band has a difference finish(?) and most importantly the grip section is 'ribbed.' The lines on the grip section feel amazing, really good to the touch. I consider it an upgrade from my AL, but you do have to be careful not to get ink in those lines because you would have to clean it out.
Mark Bacas is a popular nibmeister. You can see his work at https://www.instagram.com/nibgrinder/
I got the 580ALR with a Blade Turk grind and if I had it to do over again I would send him my nicest pen because it's an amazing grind. The Blade Turk is a mini-architect grind with a gentle curve so you get a controlled gradation of line width from Platinum UEF to Japanese M.
It's a really versatile tool. Anyone could just pick it up and write with it, but if you vary the angle up or down you can variation in width. An artist could probably build a whole career around this nib, as the more you use it the more you get to know what it can do and get the line widths you want without even thinking about it.
Here's a video demo I made of the pen & nib:
And here's an additional photoset: https://imgur.com/gallery/eXPLoO9
Mark Bacas deals TWSBI pens so I think you can just order a nib from him already ground to load into your TWSBI. This gives some additional options for nib types normally only found on Japanese pens, for example... or various architect grinds.
Anyhow, I really love the pen and I'm considering sending him my King of Pen to work on next. This Blade Turk is just such an interesting and unique grind. I'd recommend it for any artist but also anyone who just wants an interesting fountain pen nib that is still appropriate for every day use.