My original thoughts on the project were centered on a perceived simplicity in the procedures. I've since learned that I was sadly mistaken, But I have discovered a bit of qualitative proof of the possibility for success. First things first, I started by trying to gain a better understanding of how the ink cartridges are constructed, filled, stay filled, can be refilled, empty manually, and empty due to use. The color cartridges in every model printer that I was working with are all opaque. The only way for me to understand the workings of the cartridge was to dismantle it into its most basic pieces. The black cartridges for the 400 and 600 series printers are transparent, it's possible to see the parts inside and where and how the ink is contained. I also had to make sure I had the correct cartridges for the printers I was using and any special use/care instructions for the printers. I acquired the HP User Manuals from their website in PDF format. DeskJet 400 - Manual PDF The oldest and visibly the simplest printer of the set - It only holds one cartridge at a time, either black and white or color. I have three compatible black cartridges, clear, and very empty. None of the cartridges were accepted by the printer in their empty state. I was unsure as to whether the cartridges were dysfunctional to begin with or if it was the result of being empty. So I filled one with replacement ink to understand the results set forth by a refill kit. This acts as a controlled instance working with the ink cartridge because it's performing the action I desire but with the fluid mixture that is intended to be injected into the cartridge. The results however were negative. The cartridge not only failed to print, it was periodically still being rejected by the printer and eventually the refilled ink spilled out of the air hole at the base of the cartridge. At this stage, I was unable to obtain any sort of reliable response from the DeskJet 400, I expended 3 cartridges, and was forced to abandon it. DeskJet 672C - Manual PDF I drilled holes in the top of the black cartridge emptied its contents entirely and flushed the cartridge with water until it ran clear. Allowed it to dry, sealed the holes with scotch tape and refilled it with Vandyke Brown solution. This is when I discovered the strange and crucial chamber at the base of the cartridge. It is open on the bottom with an intestine-like corridor that has something to do with allowing the cartridge to breath. Because the Vandyke solution failed to match the consistency of the original ink, it did not stay inside the cartridge. It bled through this back breathing hole that is obviously designed to not leak with the proper contents. After several maneuvers to cease the cartridge from leaking, it came time to print. The result is a clogged cartridge immediately. My other plan was to fill the A and B parts of Cyanotype into separate chambers in the color cartridge for the 672C. Print an image that requires the two colors designated to those chambers to be combined. This would combine the A and B parts onto the paper and yield a Cyanotype print. I decided it was necessary to completely break apart the color one to see how the chambers are setup. The color cartridge that I dismantled ceased to work after I reassembled it. I learned that the chambers are not like individual black cartridges. They actually contain a foam pad, similar to a magic marker. Digging around the internet, I was able to find instructions on refilling the color chambers. http://www.ink-etc.com/hp1.htm http://www.refillinstructions.com/HP/H09.htm DeskJet 648C - Manual PDF This printer takes the same color cartridge as the 672C but a different black cartridge. Courteously donated to my cause by Jason Miller, This printer saw round 2 tests with Vandyke Brown and the two chambered Cyanotype test. This time around I handled the Vandyke solution much more carefully. The first time I used the solution I didn't wait for the sand to settle to the bottom of the dish and it was injected into the cartridge along with the lighter soluble fluid. This time around I decanted the liquids across three dishes. The dishes sat on top of a magnet. I thought it was pretty darn clever. It seemed to suck the heavier chunks to the bottom of the dish whereby I could extract the clear liquid from the top. Repeat across three dishes and the last dish was free of the sand. This time around, I also changed my method for introducing the solution into the cartridge. Instead of cleaning the cartridge completely, I tested it initially to confirm that it functioned, then I slowly introduced amounts of clean Vandyke solution into the cartridge as per the basic instructions for traditionally refilling the cartridge. I commenced with printing 10 of the same image. By the tenth print black ink ceased coming from the cartridge and nothing followed. There are some minor Vandyke stains evident by the wetness on spots of the page, but nothing substantial and certainly little to resolve a print. Each time a cartridge clogs, I perform the cleaning procedures outlined in the user manuals for the printers and I swab the printer heads of the cartridge. Despite this effort, the Vandyke cartridge was shot. Nothing came out after that. Or so I thought, I exposed the blank sheets of paper the next day by hanging them in my window allowing the sun to strike them for the duration of the day. By sundown, I indeed had printed something with the Vandyke solution through the print cartridges. The image isn't of the same quality as a normal ink print, but it most definitely made distinct marks resembling the original print. 20 prints with one Vandyke needle. 3 prints with an additional needle of Water. I turned to the color cartridge next. Upon testing it's functionality, I was dismayed to discover it failed to print at all. I cleaned the heads, still no print. So I referred to the refilling instructions I found and instead of removing the top cover, I drilled tiny holes in the top, poked my needle into the corresponding foam piece and injected plain water; still nothing, not a drip, not a smear, nothing resolved onto paper from this ink cartridge. I had a brand new color cartridge, so I inserted that into the printer, clicked print and an image came out, confirming that the old color cartridge is not functioning. DeskJet 812C - Manual PDF The cartridges for the 812C are different than the 400 and 600 series printers. Both color and black & white have opaque casing, the refill instructions are different, and the printer head appears to have evolved into a much more complex mechanism, however still of the same principles of design as the older models. With two partially empty black ink cartridges left, I decided to try Ammonium Dichromate diluted at 1:27. Using the same idea as with the round 2 of Vandyke, I tested the cartridges first, resolving standard black & white prints before I began injecting the solution. The AD had a strange effect on the ink, causing it to thin considerably. It began leaking straight from the microscopic printer heads themselves. Desperate to see anything happen, I cleaned up the cartridge and quickly inserted it into the printer. 10 prints later, I have something marginally resolved and then it lends itself to simply bleeding onto the page. Nevertheless, the bleeding itself shows the combination of ink and AD. So the AD successfully passed through the print head, but failed to successfully print my image. After several minutes, the running and dripping ink dried and what was inside the cartridge seemed to congeal. Ammonium Dichromate stopped printing. The final ink cartridge, with keeping the Cyanotype chemicals physically separated not a real possibility at this point, I decided to combine them and try my luck with the same process as AD and Vandyke. Equal parts of A and B solution are dripped into a dish, first 20 drops each, then 35 more drops each. There were no results printing with the Cyanotype, and I suspect that the resolved parts of the images created by this print cartridge are a result of residual chemical build up from the last process, as it certainly leaked the thinning ink into the printer and over the gears inside it. This is again evident in the exposed state of the paper, after showing it to the sun for the day. The prints show properties unlike Cyanotype, in that they are just not blue, and in fact the same shade of brown as the AD stains. This leads me to wonder how the print heads control the ink. Initially, I saw the smallest pin holes and thought they touched tiny droplets of ink to the paper with some machine effectively controlling this process. I'm beginning to think that the ink contained in the cartridges is formulated in such a way that maybe electricity is involved in the printing - the printer head and the contact to the printer from the cartridge is all copper and that means electricity is there to some degree. As if electricity arranges the specially formulated ink onto the face of the print head and when it kisses the page it is a calculated bleed. 24 hours later, I have changed my mind about the ink cartridges and how they handle their contents. I did have some success printing with Vandyke and even a little with the Ammonium Dichromate through the cartridges. I think that it mostly has to do with the consistency of the ink and its drying properties. It dries quite rapidly exposed in open air, unlike the non-silver chemicals which evaporate and behave much more like water.