Ink Cartridge Stand

This is a simple Fountain Pen Ink Cartridge holder. Its primary purpose is to hold ink cartridges and cartridge converters face-up so they can be filled with ink via syringe. Inspired by similar designs, this version has a minimal approach to holding (3) cartridges or converters in the upright position for filling. As many inernational and proprietary cartridges are slightly tapered, this version is based on 8mm hole diameter to allow the cartridges to be inserted opening-up.