Does anyone make a Continuous Ink System for old DesignJet 750C plotters? My DesignJet 750c is still a workhorse for doing banners, quick signs, and posters, but I'd like to find a CIS for it since changing cartridges when the 42ml (or 41ml?) cartridges run out of ink usually means a ruined print (and when doing 12' banners with it, that's a lot of wasted time and paper.)

Anyone know of a CIS system for an HP DesignJet 750c?

Print head life might be the issue here - the HP 45/44 cartridges are designed to last noticeably longer than one-cartridge full of ink so they don't have any premature failures that customers would complain about, but I'm not sure how many refills you'd get beyond 2-3. If you fit a CIS, you might find your problem simply shifted to quality problems due to the disposable printhead nozzles wearing out.

The HP 45 black cartridge used in your plotter is also used in a lot of inkjet mailing address printers now for which some bulk systems are available ... for example http://www.collinsink.com/hp45a_bulk.php
* 440 ml bulk system
o Equivalent to 11 cartridges
* 840 ml bulk system
o Equivalent to 18 cartridges
With some creative work something like this could be retrofitted I bet.