ink level
 

I have a HP 3550 printer on a Slackware 9.1 system. Could someone tell me how could I find out the ink level?

Thanks!

Printers don't have any way of detecting the ink level. They're programmed to tell you you've run out when the're still half full so they can make more money selling refills. Buy a spare refill and keep it somewhere cool until you see the print quality visibly deteriorate.