for cartridges with the printing matrix on the bottom:
if you leave them open to air for a very long time they will dry up on you. however, if you are only going to leave them sit for a few months then wiping the matrix with rubbing alchohol seems to work great at getting the surface residue off.
best advice.... dont buy more ink than you need to.
Possibly. Some do, some don't, any ink cartridge has an expiration date, and they all react differently to different environments. Some printers have print heads on the printer, some on the cartridge.
for cartridges with the printing matrix on the bottom:
if you leave them open to air for a very long time they will dry up on you. however, if you are only going to leave them sit for a few months then wiping the matrix with rubbing alchohol seems to work great at getting the surface residue off.
best advice.... dont buy more ink than you need to.