a short note on the TWSBI pen you linked:
the TWSBI diamond has had a more value-oriented small cousin for a while now, the TWSBI eco (~30 USD compared to the 50something USD for the diamond). like the diamond, it’s a piston filler, but the overall design is a bit simpler to manufacture (the diamond’s faceted barrel is smooth in the eco, it relies on the cap design instead to prevent rolling off the desk) and you don’t get the swappable nib/feed units you have in the diamond.
being able to swap between different size nibs could be a valuable factor for drawing use, as you don’t have to buy multiple pens and keep them all inked up.
a short note on the TWSBI pen you linked:
the TWSBI diamond has had a more value-oriented small cousin for a while now, the TWSBI eco (~30 USD compared to the 50something USD for the diamond). like the diamond, it’s a piston filler, but the overall design is a bit simpler to manufacture (the diamond’s faceted barrel is smooth in the eco, it relies on the cap design instead to prevent rolling off the desk) and you don’t get the swappable nib/feed units you have in the diamond.
being able to swap between different size nibs could be a valuable factor for drawing use, as you don’t have to buy multiple pens and keep them all inked up.