“Print is cheap”… adventures with Continuous Ink

I’ve been curious about CIS systems for a while, but they always seemed like overkill. I finally decided to give one a try after looking at the cost of refills for an HP OfficeJet Pro 8500 – the CISS is 15% cheaper, refills cost 90% less, and it only takes about 30 minutes for the one-time setup. For your amusement, here’s a blog of my experience; I’ll update it over time.

What’s a CISS?

CISS is continuous ink supply system – a third-party inking scheme for inkjet printers. Rather than installing replacement ink cartridges, a dummy cartridge goes in the printer with a siphon hose that connects to a large ink reservoir outside the printer – often 4-5 times larger than a typical cartridge capacity.

It’s easy to justify a CISS if you print a lot, or even if you don’t – they’re surprisingly cheap compared to a full set of ink cartridges. In the case of my HP 8500, a CISS costs USD$100 from InkProducts.com while a full set of HP 940XL cartridges costs USD$115 (and has 1/4 as much ink). The CISS kit includes a full set of ink, and refill ink costs just USD$40 for a full set (vs. USD$460 to get the same amount of ink in HP refills).

[Edit 24-Aug-2010] After 8 months of typical home use, we’ve used up half of a 120ml black ink refill bottle, but the 3 colors are still going strong from the original CISS kit; I’m only just now ordering refills for them. So, about $120 spent at InkProducts.com (CISS kit + black refill) will last about a year of our use – much longer than a set of HP cartridges would have. A full set of 120ml refills will cost ~$50 and last us for another 2 years.

Getting started

My system from InkProducts showed up quickly – within 3 days of the order. Here’s what the kit included:

  • Internal ink cartridges (C, M, Y, K), tubing, and external ink reservoirs – all already connected and pre-loaded with ink
  • Four syringes with short blunt needle tips
  • Instructions with color step-by-step photos
  • Double-stick tape for the ID chips

1) Moving the ID chips

The first step is the most time-consuming – it involves prying the ID chips off your old HP cartridges. I’m fairly experienced with microelectronics, and I was a little nervous that I’d damage the chip while prying the flexible circuit board off with a knife. All ended well, but a screw-up would have meant buying another USD$20 HP cartridge just to get the chip, so work patiently.

As each chip is removed, it gets attached to the dummy cartridge of the corresponding color. I wouldn’t be surprised if the chips also contained the color ID, so it’s best to do them one at a time to keep from getting things mixed up. InkProducts marks the location on the cartridge, so it’s pretty simple. The die-cut double-stick tape is a bit too large for the opening on the dummy cartridges, and needs to be trimmed with scissors.

2) Installing the dummy cartridges

With the printer still on, open the lid to access the print heads; the heads will move into position. Now would be a good time to turn the printer off. Also, put on some rubber gloves and take off that nice shirt – you might get ink on you.

Insert the new ink cartridges and route the flexible tubing as the instructions show. Beware of keeping the external ink reservoir at the same height as the printer so gravity doesn’t flood the printer or keep the siphoning from working. Also, be careful that the tubing doesn’t get pinched around any tight corners (like in the door covering the cartridges).

An important note – there’s an air plug on the internal ink cartridge: leave it sealed! The warning in the instructions is actually written backwards. The internal cartridge air vent must stay plugged, and only the air plug on the external ink reservoir should be uncapped. If you unplug the internal one, the siphoning action can’t work to pull ink from the external reservoir – plus, the reservoir could drain into the printer. (Bad!)

3) Priming the line

With the printer still off, pull out the print heads. Use the provided syringes (use a separate one for each color) to suck ink through the line and make sure all is working. The ink won’t be “easy” to suck out, but it won’t be difficult either. In my case, the black ink line wasn’t flowing; pulling the cartridge out and reseating it fixed the problem easily.

Clean out the syringes and store them for next time you need to refill. Use care, because the ink will stain your sink.

Air in the line

Depending on your printer, there may be no reason to panic if you see a few air bubbles in the line. For my HP 8500 the internal cartridge has an internal reservoir; it just gets constantly refilled from the external tank. In this design, any air bubbles from the external line just bubble to the top of the internal cartridge and don’t get air in the print head line. Though if you let a lot of air in the line, it’d make the ink levels in the internal cartridge drop too low, and that wouldn’t be good; the instructions show how to use the syringes to suck air out of the ink cartridges as well.

The gotcha to watch for is air bubbles in the hose between the internal ink cartridges and the print heads. They can be introduced when the system is first installed or during refills, and this can cause the print heads to fail prematurely. CISS kits typically come with a suction tool to prime the line from the print head end; some seem to have a squeeze pump instead; mine came with syringes and needle-like tips.

4) Testing it out

Powering the printer on took a very long time. This model goes through a very long startup sequence sometimes, perhaps when it thinks inks have been changed. Last time was when the printer was new, and both times it took nearly 15 minutes to complete the printhead cleaning cycles.

I loaded a color document in the scanner and ran several color copies with excellent results. If I was going to print photos, now would be the time to color profile the printer with the new inks. First, I’d want to run a lot of large color prints to be sure the ink line from the cartridge to the print head was refreshed with the new ink. (Alternately, drawing about 1mL from the ink line using the syringe would do the same thing more reliably.)

False ink status warnings

The printer reports the amount of ink in the cartridge based on how much it thinks it’s used, not based on any actual measurements. So, by moving the old chips to the new cartridges the printer continues to think it’s the same empty cartridge. My black and yellow cartridges still show as empty and the cyan and magenta report being very low.

[Edit 24-Aug-2010] As time has passed, the Y and K ink warnings never did reset – now all the ink levels report as empty. Fortunately the on-screen warnings have stopped popping up, though the ink status still shows a warning on the printer.

ID chips and “resetting”

The OEM (original equipment manufacturer) ink cartridges have small circuit boards with authentication chips attached. Depending on the CISS kit you buy, it may come with chips already installed, or you might need to salvage a set from your old cartridges (as I did). Depending on the printer manufacturer these chips need to be reset once the ink runs out; the CISS kit probably includes a reset tool in that case. Some manufacturer’s chips (like Lexmark) can’t be reset, so CISS systems can’t be used.

Manufacturers make PR claims that the authentication chips ensure quality, etc., but truly it’s done to make refilling more difficult and protect the revenue they get from ink cartridges (which easily cost more than the printer over its lifetime). I recall that in some jurisdictions (EU?) the use of chips to prevent 3rd-party inks has been made illegal, but in the USA it’s still standard fare.

Ink: Dye vs. Pigment

There’s more to this topic than I care to learn, but I discovered that you need to watch what you buy. E.g., apparently dyes will clog printheads that are designed for pigments, so buying any ol’ “bottle of ink” doesn’t cut it – get the right stuff for your printer.

Fading and color matching

There’s lots of concern among the photo community whether the inks are colorfast and how UV resistant they may be over time. I haven’t dug too deep on this because I don’t print photos locally, but plenty of folks claim that the more reputable CISS manufacturer inks are on-par with the OEM version.

Regarding color matching, it’s a good practice to color profile your printer whenever you change inks or papers anyway, so this really isn’t a concern. If anything, since you’ll be refilling the CISS inkwell less frequently, you’d need to profile your printer less often.

Sponges vs. seals

Apparently there’s an issue with sponges used in some brands of dummy cartridges leaking out over time and causing a mess inside the printer. Apparently the InkProducts system I bought doesn’t use sponges, so I hope never to have this problem. Fingers crossed.

Where to buy

I happened to buy from InkProducts.com because their site appeared more knowledgeable about my particular printer. Other sites seemed to treat the inks generically, while these guys make a distinction about pigments and the bad effects of using dyes. They’ve also been around for a lot of years, and there were positive comments about the quality of their inks in discussion forums going back several years.

I did notice that certain companies focused on perhaps one brand of printer, and for that brand they were more prominent in the search results and discussions. I also noticed other sites offering to include the chips.

Got any questions, comments, or corrections? Let me know!


7 Responses to ““Print is cheap”… adventures with Continuous Ink”

  1. How has your experiment turned out?



  3. FYI, this system is still working like a champ! We’ve used about 2/3 of the original black ink, and it’s time for a refill. (The other colors still have 60%+ left.)
    I’m switching to their newer dye-based ink, since they claim it can be mixed with the current pigment ink in the reservoir. The 120ml bottle is a a good balance between price and the volume we’re using. (If I was worried about color profiling, I’d flush the line to the print head when changing inks, but since I’m not printing photos I don’t care.)

  4. Bernie Says:

    Are CIS systems really illegal in the EU? Given the ubiquity of eBay it would be difficult if not impossible to enforce it. I use CISS with my Epson and am delighted with it. I print anything and everything in high quality full colour and never have to worry about the cost – the complete opposite of using OEM cartridges. I highly recommend CISS.

    • Hi, Bernie.
      I didn’t mean to imply that CIS systems were illegal in areas of the EU – rather, that I’d read that authentication chips had been outlawed in some EU jurisdictions so manufacturers couldn’t prevent 3rd party inks from being used. I’ll edit the text to be clearer.
      Cheers, Richard

  5. bruno martin Says:

    Hi Richard,

    I also have a hp8500a and bought a CISS. However there is a strange issue that I`ve noticed with my printer:

    as soon as the printer detects that any one of the cartridges installed has been refilled (page count over certain threshold), the printer stops getting out of sleep. So each time I need to print something, I first have to reset the whole printer and send the print job before it goes to sleep. Turning sleep mode off didnt change anything!

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