Bottled Fountain Pen Ink

About

Fountain pen ink by the bottle, can be used in any fountain pen that either has its own filling system, like piston- or vacuum-filled pens, or in most cartridge pens by fitting a converter . It's usually much more cost-effective than using cartridges, avoids the plastic waste, and is available in way more colours and ink types, opening up options like sheen and shimmering inks and waterproof inks , if you're ok with taking a bit of extra care.