Let me clarify the different cartridge designs and filling procedures for you: some cartridges, such as the R2400 and R1800, as well as the older model 1400/1430, R1900, R2880, have/had an exit chamber that draws ink from the main cartridge body and leads to the exit valve. The cartridges with the circular shaped exit chamber must be vacuum filled in order to get ink into the exit chamber, which is necessary for proper ink flow and function of the cartridge. The newer style 1400/1430, R1900, R2880 carts have a different "exit chamber" that is positioned at the bottom/front area of the cartridge, and has several openings that allow ink to flow freely from the main cartridge body, so ink can simply be injected into the cartridge using the syringe and blunt-tip filling needle. If you find it easier- you can vacuum fill the new model carts, by plugging the air vent hole and drawing a vacuum as per the previous model's instructions, but it's not necessary with this model. Though, it IS still necessary for the R2400 and R1800/800 model carts (which are bottom vacuum filled)
As per the instructions, you should fill/refill a cartridge with ink (air vent open or closed- it doesn't matter), then plug the fill hole, tap the cart exit valve down a few times on a folded paper towel to force ink down/air up, open the air vent holes, then install the cart into the printer and let it sit for a few minutes before doing cleaning cycles or printing nozzle checks.
No, we no longer sell carts for the 2100/2200 model printer.
I hope this helps clarify the reasoning behind our different cartridge models and their specific instructions.
Best regards and happy printing~ Dana