Texas Chrysotype Process
I am Richard Puckett, introducing my Texas Chrysotype process, which was presented in the March/April 2012 issue of View Camera. If you have not got access to back issues of VC, visit unblinkingeye.com.
The process is characterized by:
- Fine grain
- Excellent Dmax and Dmin with good tonal separation between the two extremes. In other words, true continuous-tone images
- Dry print out. You determine correct exposure by direct examination.
- No humidification of paper. For the January 2012 proof of process demonstration to members of the Austin Alternative Processes Group, I used Arches Platine stored in a closed plastic bin with 4 pounds of silica gel. RH was 29%.
- Economical 10% gold chloride solution.
- Key is the addition of ascorbate to ammonium ferric oxalate. Some of the gold precipitates out to form a foundation that smooths out the image and greatly extends its tonal range.
- Absolutely repeatable. Make print after print of the same negative.
- Standard clearing as for ziatypes.
- Contrast control by various means.
I have put six samples up in my APUG album. Incidentally, I have developed a (significant) variation on the process that makes it equally simple to print with palladium and platinum, as well as gold and platinum. I will be announcing that process later this year in another magazine article.
Thank you for the Info, how does it compare to the other Chrysotype process in terms of image tone?
Hello Richard and a warm welcome to APUG. Looks like a wonderful process.
How it compares to other processes
I was trying to print my texas revolution negatives using the traditional ammonium ferric oxalate/gold chloride approach, both Ware's and Sullivan's ziatype with gold instead of palladium. I expect you know what that looks like. I could not bear to print my negatives as grainy, gritty, contrasty red images. With ascorbate added to the afo, a base of gold precipitates out onto the paper and eliminates grain while smoothing out tonal separation and extending the range out to between 9 and 11 stops, depending on the paper you use (wider range with clearprint cotton rag vellum; narrower with Arches Platine). Your negative is also important: negatives exposed for printing on silver gelatin are better than ones exposed for Pt/Pd printing. Comparison? If the other processes were 35mm HP5+ printed to 8x10, the texas chrysotype would be 35mm Iflord Pan F+ printed to 8x10. I don't know if the below image can be enlarged; larger one is in my album.
Versatility of the chrysotype
Hello, Jeff and Sirius,
Yeah, it is neat! I've been invited to present it at APIS in 2013. Good things about this process are:
- Fine grain: as in none up to just apparent (depends on how much ascorbate you add to afo)
- Controllable contrast: boost contrast by substituting a drop or two of plain sodium ferric oxalate for the afo-c); reduce contrast by sizing paper with arrowroot starch or gum arabic (clear gum arabic prints with 2% HCL acid!), or by substituting platinum or palladium for gold on a drop for drop ratio, or just use rag cotton vellum
- Full tonal range: retain shadow detail and also highlight detail with straight afo-c and 10% gold
- Economical: gold for an 8x10 costs $2.25 at current price; about $1.40 for my whole plate negatives
- Dry print out by inspection -- you brush on the sensitizer and place the print in a dark, dry place and when fully dry, print
- First bath is usually ice water to keep the print from darkening further
- Clear in usual acid/water/edta/water/hypo clear/water/edta/water succession of baths
With this process, I can make a lovely print on the spur of the moment...
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Here is a link to my presentation at the APIS in Santa Fe, last October, which I mentioned earlier, above. Incidentally, I have refined the process considerably in the past 2 years. For maximum smoothness of tonality, and a rendered latitude of 11 stops or more, prepare ammonium ferric ferrous oxalate by adding just 3 or 4 drops of 1% ascorbic acid to 10 ml of 40% ammonium ferric oxalate. Only a small amount of ferric iron is converted to ferrous iron, but enough ferrous iron is there to obtain complete print out on totally dry paper. The contrast is quite low, grain extremely fine to invisible, and latitude quite wide. Mix the amm ferric ferrous oxalate with 10% gold at a ratio of 3:4. That is, for an 8x10, 9 drops of ammonium ferric ferrous oxalate with 12 drops of 10% gold chloride. You will likely have to add 1 drop of 26% ferric oxalate (no ascorbic acid) to every 3 drops of ammonium ferric ferrous oxalate. Therefore an 8x10 would need 4 drops 26% ferric oxalate, 9 drops ammonium ferric ferrous oxalate, 12 drops gold. For some negatives, you might even have to add 6 drops of 26% ferric oxalate! (Unfortunately, the dichromates won't do for boosting contrast with gold -- they grain it up. Only ferric oxalate works with no adverse impact on the image quality.) You will see ochre staining from the excess iron, but it clears out by the second bath. The first bath has to be a very weak solution of ice cold sodium sulfite. I do not say "has to be" lightly. Listen to what I explain in the video, and watch my other videos on youtube, especially the Karytype process video (printing out the formerly impossible combination of gold and platinum):
IMPORTANT UPDATE TO THE TEXAS CHRYSOTYPE
Use Arches Aquarelle hot-pressed paper, or other gelatin-sized hot-pressed paper. For a 4x5, 3 drops 10% gold (12 for 8x10), 6 drops AFFO (10 ml of ammonium ferric oxalate to which you add 3 to 9 drops of 1% ascorbic acid -- for this update, I prefer 7 drops of C). In other words, use twice as much AFFO as gold. In the unlikely event you need more contrast, either switch to Arches Platine paper or add a drop or more of 26% ferric oxalate. Brush the sensitizer onto the Arches Aquarelle paper. Print out fully. Immerse the print in a first bath of 1% nitric acid (you can easily make your own or purchase it from jeweler supply companies for testing gold purity -- the cliche "acid test" is with nitric). Observe the print turning gray with some purple or dark lavender staining also appearing. When you discern an acceptable balance of the two immediately wash the print in running water. Follow through with 3 successive baths, interposed with water washing, of course: 10% tetrasodium EDTA for 15 minutes, standard hypo clear for 10 minutes, and a final tetrasodium EDTA bath before the 45 minute wash. The quality of the image will be identical to the same negative printed on palladium. Note: If you choose not to use a weak nitric acid bath, your print will likely be brown with heavy brown staining in highlights. Tetrasodium EDTA and sodium sulfite will not clear the staining. Nitric acid will and it will turn any brown gray. I have proof prints drying now, which I will upload later this week. All along, I was using the wrong papers: Arches Platine and Clearprint Vellum, when a gelatin-sized paper would have given me this level of quality over 2 years ago.
Last edited by Richard Puckett; 06-22-2014 at 12:18 AM. Click to view previous post history.
Reason: Typos, added note about contrast.
Update to printing the Texas Chrysotype on Arches Aquarelle hot press or other gelatin-sized paper. You do not need to double the ammonium ferric ferrous oxalate (AFFO). That was an atavism from my Electrumtype Kary. On further testing, I have found that using AFFO at 2:3, 3:4 and 1:1 (all AFFO:Au), you get the same three dimensional effect and can forgo the first bath in nitric acid. I most recently found that a final bath in sodium dithionite (Rit color remover is sod dithio+ sod carbonate, hint) produces a lovely image that is very dark brown/purple so subtle that mid zones render as grays. And, again, it is a chrysotype with no grain, with extremely wide latitude, and superb sharpness. BTW, the regular formula (3 to 9 drops 1% C added to 10ml 40% ammonium ferric oxalate) applies to printing on gelatin-sized papers; w/3 drops 1% C, you'll get amazingly low contrast tones and will likely need 2 drops of 26% ferric oxalate to raise the contrast (you'll need rit color stain remover to clear all the iron). At 7 drops of C you'll be able to print negs perfect for grade 2 silver paper straight.
Here's a 4x5 contact print, 10% gold printed out on Arches Aquarelle. The formula was 3 drops 10% gold chloride and 3 drops of ammonium ferric ferrous oxalate (7 drops of 1% ascorbic acid -vitamin C- added to 10 ml of 40% ammonium ferric oxalate). This took about 3 minutes to print out fully on dry paper -- no humidification chamber, no heavy breathing on the paper, no clothes steamer, just dry it and print it.