Who'd have thought it? A fibre tip pen that's refillable with an international standard ink cartridge? That would be a Yookers. Oh, and you can replace the nib sections too!

All you need do is select the Yookers pen that takes your fancy, and if you want something other than a 1.0mm tip, you can customise it with the tip size of choice before selecting pretty much any colour of ink you like, from many different brands.

The Yooth 591 is simple in design but the attention to detail is irresistible. The barrel unscrews so that you can fit the ink cartridge, but this is also all that's needed to swap in a different-sized nib section. The grip area is comfortably ridged, with a raised area just before the tip, to stop your fingers getting covered in ink. This ridged profile also serves to secure the cap in place: the cap clips on with a satisfying pop.

It's fitted with a robust 1.0mm tip, the shaft of which is protected by a steel sheath, and is supplied with a blue ink cartridge. It will also take a mini converter for use with bottled ink.

The metal barrel is a plain black laquer; the cap is branded with the Yookers logo in white and features a polished metal pocket clip and cap end.