I’m a sucker for quality stationery that comes in colourful little packets or boxes, and these Kaweco cartridges fit the bill. Highly pigmented in a small range of useful shades. Perfect for use with your Kaweco fountain pen but are a 38mm standard size and will fit most fountain pens. (note: not Parker/Lamy)

Palm Green - Makes me think of Hogwarts letters, which can only be a good thing

Box size - 6 cartridges