Two sets of the cartridge(s) are required for refills to work for your printer. You must alternate the one(s) from the printer and a backup 2nd set.
When refilling the cartridges for your printer, there is a small chip on the printer cartridge. If you remove the empty cartridge, fill it and put it directly back into the printer, the printer will remember that it is the old cartridge and not let your print. You can trick the printer by placing or alternating the cartridge with a spare one. Doing this will cause the printer to forget the previous cartridge and allow you to continue to print.
Example. You will have two (2) black cartridges; when cartridge “A” black runs empty, take it out and put in cartridge “B” black cartridge and then refill “A” black cartridge. When “B” black cartridges run empty, take it out and put in “A” cartridge.
If you do not currently have a second set of cartridges for your printer, Printer Refillers caries most models of ink cartridges ready to go.