The TWSBI Diamond 50 Ink Bottle is a glass inkwell designed to match the TWSBI Diamond fountain pen range. Sporting specially-designed filling mechanisms, they work particularly well with TWSBI Diamond pens, but include features suited to filling almost any fountain pen.

An internal reservoir ensures that you can use the inkwell to fill almost any bottle-filled pen, even when the ink level is very low. Take this out, and the ink tube attached to the aluminium neck extends down to the bottom of the bottle, letting TWSBI Diamond pens fill themselves until your bottle is almost dry. Remove the nib and attach the pen to the end of the tube to fill, making filling easier and making spills less likely.

The end of the tube is also the same size as the opening in a standard International converter, so you can use the same method to cleanly and easily fill many brands of converter.

Available with a variety of cap colours to allow distinction between the inks stored within - great for those who have lots of inks on the go at once!

Supplied as an empty inkwell, so you will need to fill these inkwells with bottled ink. We recommend using Diamine Ink, for their wide range of colours, but any fountain pen ink will work fine.