This is the story of someone who began refilling their own cartridges, and through that experience went into the business of selling refills and the idea of refills to others.In the early 2000’s, my cartridge ran out of ink.  It was a Canon BCI-21 series cartridge (printer was a Canon MultiPass, taking a BCI-21 black and BCI-21 color ink cartridge).  The 2 cartridges could be substituted with the thicker Canon BC-20 inkjet cartridge, which would offer more black ink and require that the printer prints in monochrome mode (black only).A set of new inkjet cartridges from the college bookstore cost around $40, a heavy price for a college student, and about 1/2 of what a new printer would cost.  In fact, you can pick up a printer for as low as $60 today (for an inkjet printer).  Taking a closer look at the inkjet cartridges, a light bulb went off…