We at Colormagic in the UK have done this for years, we buy back empty Ink cartridges then what's left in the Ink cartridge we take out and then refill cartridge and re-chip cartridge then we re-sell the full cartridge, then we have a lot of empty cartridges that we then refill with our high-quality compatible Ink and sell. We sell over 2000 Roland cartridges each month and properly 2500-3000 Mimaki cartridges, I must tell you that this is all done by proper filling machines so we get no air in the cartridges that can cause issues.