Photogravure - Phoenix Tissue Processing
Some of you may know that I have been mostly concentrating on Photogravure for my work and I figured, in case anyone is interested, I would post my processing guidelines for the only commercially available pigment tissue, Phoenix. The same is also posted on my website for reference.
Photogravure – Phoenix Pigment Tissue Processing
If you are one of those individuals who are interested in venturing into photogravure, (if you have not already) you know that the only choice of pigment tissue is Phoenix, sold by Jennifer Page of Cape Fear Press. First of all, hats off to Jennifer for bringing it to us, as there would be otherwise nothing available for this venerable process. McDermid Autotype and McGraw, were the old standards, and let me begin by saying that Phoenix is neither one. It doesn’t mean it’s bad, but it doesn’t behave the same as the aforementioned, under the same conditions, at least in my experience.
Disclaimer: what you will read is based on MY experiences with this tissue, based on very exhausting and extensive testing. Nevertheless, because of the very nature of photogravure, water quality, alcohols, personal touch, karma, stars and planets alignments, wind direction and moon cycles, all contribute to the final outcome. Ok, maybe I’ve exaggerated a bit, but what I’m trying to say, is that the following are guidelines, based on my own experiences. This tissue comes with no data sheets or instructions so, at the end of the day, you really are on your own and I encourage you to first find out for yourself if my guidelines can be duplicated and applied in YOUR studio and if they need tweaking. It is also helpful to ignore various old, and at this point very outdated literatures out there when it comes to processing tissue, as again, it relates to materials no longer available.
Sensitizing: the first problem with Phoenix tissue relates to sensitizing. We know that to control contrast, we would normally use lower concentrations of potassium dichromate, usually 2.5% to achieve higher contrast, with 3 to 3.5% being “normal”. Well, Phoenix sensitized with a 2.5% solution will yield simply a mess. Basically, it is just not sensitive enough, and increasing exposure does not make it better by any means. You will see blotches and uneven development after it comes out of your developing water. Things get better at 3-3.5% but there are still some issues at those dilutions, mainly mottling and things still looking blotchy at times. I have now settled for a 5% solution, and even though that tends to reduce contrast, which can easily be compensated for through etching and linearization curves, along with inks at printing time, it gives a very beautiful, even, and trouble free tissue. I sensitize at 53º for three minutes. Data from Jennifer at Cape Fear points that a shorter time at lower temperature (48º) is beneficial, but frankly I have not seen that. Reticulation, mottling, uneven development, from what I have seen, have ALWAYS had something to do with lower concentrations of dichromate solution, temperature and alcohols.
Exposure: I work with a Nu-Arc Flip Top unit, equipped with a 3K bulb, which is 24 inches away from the vacuum frame. My unit is setup as such that each exposing unit is roughly one second. I use Mark Nelson’s aquatint screens (medium), which have a density of roughly .93 when measured on my XRite 361T UV channel, and also Jennifer Page’s analog screens, which are less dense but more “natural” looking. Both screens are fantastic, but Mark’s screens, having been produced on an image-setter, will give incredibly fine grain and superb detail, while Jennifer’s screens resemble a more traditional dust grain look. Again, both are fantastic choices, if slightly different. My normal exposure, with a PDN screen and tissue sensitized at 5%, is 35 units for the screen and 45 units for the tone positive.
Lay-down and Development:
Very Important! Phoenix tissue DOES NOT like alcohol at high concentrations. You do not need to use alcohol in the lay-down process, or if you must, do not go over a 50% solution. Frankly, distilled water, chilled down to 50-55 degrees, works perfectly fine and there is no reason to use alcohol. At that temperature, slide your tissue in, keep it under water for about 10 seconds, flip it, and position it on your copper. Out! Squeegee, from center out once, from each side, and no more. Position two sheets of paper towel on top and, with the palm of your hand, push down and out with a bit of pressure. You’re done. A word on squeegeeing only once, from center out: unlike Autotype, the backing paper on Phoenix seems quite delicate as well. Too much pressure or passes with the squeegee, and you will raise fibers, while opening up tiny pinholes, which will result in blisters in your water development. It is not a huge deal, as the ensuing “cauliflowers” or any marks, do wash away after a couple of minutes in the hot water.
Note: if you encounter problems with excessive “devils” at etching time, before you start looking into neutralizing your acids, or other esoteric remedies, do this: boil a gallon of distilled water, chill it and use it for your lay-down. All water, and even distilled store bought, will have some gases, which create tiny bubbles at lay-down and the subsequent annoying devils at etching time. By rending your water totally inert, the problem pretty much goes away, or at least 99% of it.
DO NOT flood your plate with alcohol prior to development. Again, I have seen nothing but trouble when using alcohol prior to immersion in development water. Phoenix, overall, seems a lot more delicate than Autotype and alcohol at this stage offers no real advantages. I keep the plate in the 115 degrees water for 4-5 minutes before attempting to peel off the backing paper. You can try after 30 seconds or one minute but I can almost assure you that it won’t happen. At the 4-5 min mark, it comes off like a loose Band-Aid and all is well, at least in my book. Continue developing for at least 5 minutes. You can test gently with cotton balls but you will see that at 5 min, there is still a good amount of pigment coming off. If you are squeegeeing, after development, you want most of that pigment off if possible. I find that at about 8 minutes, after the backing paper comes off, residual pigment is minimal.
After development in hot water is completed, turn your water down to 65 degrees (a Haas Intellifaucet is a smart purchase) and slowly bring your tray down to that temperature. That will firm up the gelatin. Since my tap water is quite horrible, I keep a jug of distilled water chilled to 53-55 degrees, and flood my plate when it comes out of the cold tap water. Makes a huge difference for me, as my water is very hard and just quite bad.
Now, for alcohol and drying: common gravure process will have you submerge the plate in a 75% alcohol solution for at least 5 minutes. Please do go ahead and do this with Phoenix and see for yourself what happens. You will see the tissue shrivels up and acquire an “orange peel” look, kind of blotchy, and you will also likely open up a myriad of pinholes. The optimal concentration of alcohol, to achieve moisture balance with Phoenix is 55%, Isopropyl or Methanol. I use Methanol because it is gentler and odorless. You do want to use a respirator though, because the fact that it doesn’t have an odor, it doesn’t mean it is healthy. Time in alcohol is also somewhat critical, but I have found through experience, an interesting fact: simply flooding the plate a few times, and then squeegeeing, is good enough. You can keep it in the alcohol 2-3 minutes, but I have not seen any benefits from it. Either way, I would not go passed the 3 min mark. After that, the tissue seems to become quite dry and prone to pinholes. Temperature seems to be important as well. Keep your rinsing distilled water (if you need to use it) and alcohol, at 53-55 degrees. The cold and consistent temperature will keep the gelatin firm and allow you for a firm but gentle squeegee to eliminate the surface alcohol solution. Don’t be afraid to use the squeegee, with not too much pressure of course, as the gelatin is quite hard and a lot more resistant than you think. Make sure you clean your squeegee blade with some Isopropyl prior to usage. I find that the occasional streak on the tissue, even though slightly visible, does not transfer to the etching. More conventional methods of eliminating a low concentration of alcohol (55%) on the surface, may create issues for certain images, as it always does not evaporate as swiftly as 75% or even higher, and you may end up with drying problems that will become evident at etching time. I finally dry the plate at a 45º angle for 5-6 hours at 60% humidity, before proceeding to etching. If you work late in the day, simply let it dry overnight and etch the next morning.
Last edited by MaximusM3; 01-17-2013 at 04:07 PM. Click to view previous post history.