Do you need two ink cartridges for a printer to work?

You can just have black but you can't just have color because it will be off color. Your images will be ruined hence, wasting your ink and time. I definitely recommend if you are only to use one, use the black one.

Thats hard to answer with a yes or no becasue some models require both be full others do not require the color to be full. In order to get ideal color photos you need black ink. I know it doesn't sound logical but you would be amazed how much more crisp a color photo will look when its shadows and certain lines have black ink. For those printers that refuse to work unless the color is not empty there are little tricks. You can look for videos on how to change the color catridge ink yourself and some of the videos will show you the particular gold contact points you can put electrical tape over (usualy 4 gold pins/connectors) that will make the printer think that the color is always full. This way you need not go out and buy a color cartridge when your just printing b & w documents all day. Some of these mfg and models darn right tick me off for there is no reason to stop a person in their tracks at 4am to stop printing just becasue it is out of color and you don't need color. It is frustrating enough to toss it out of a tall building. I'm not sure if I answered your question but I hope this helps Coley

for some printers it requires you to have two ink cartages to work. i know the dell all in one requires you to have both

That depends on the printer...