Printing Cyanotype on Alternate Surfaces
Cyanotype can be printed on just about anything. The most common surface aside from paper is fabric, and then perhaps glass and wood, but I’ve also seen it printed on porcelain, eggshells, metal, bark, and bone. This chapter will discuss methods for printing cyanotype on fabric, glass, and wood.
Printing on fabric has been part of cyanotype’s history from the late 1800s, and continues to this day with several companies selling readymade sensitized fabric sheets or squares. Cyanotype will print well on any natural fiber fabric like cotton, silk, linen, rayon, old cotton sheets, t-shirts, gauze, unbleached muslin, and painter’s canvas. The tighter and finer the weave of fabric the deeper the blue and the finer the detail.
Wool, although a natural fabric, can be problematic because of the lanolin inherent in the fibers which prevents absorption of the chemistry.1
Silk, if it is not PFD or “prepared for dyeing”—free of surface treatment2—will need a wash to remove the silkworm’s natural gum “sericin”: take 10% of the fabric’s weight of sodium carbonate and combine it with 40% the fabric’s weight in water. Simmer the silk for 30 minutes in this solution, allow to cool and then rinse very well so no longer alkaline, adding a splash of vinegar to the final rinse.3
Synthetic fabrics are not good choices because the fibers don’t absorb the solution well and then after exposure the image washes off, leaving a pale, grainy print.4
Before committing to a lot of one fabric, take a piece of it and expose, process, dry, and then tear it in half and wash one half to test it.5
Wash, rinse, and dry any fabric before coating to remove factory sizing, starch, or who knows what else fabrics are coated with, or else brown stains may occur.6
The quantity of cyanotype solution needed for soaking large pieces of fabric is much greater than a typical 100 ml formula provides. It may be that as much as a gallon of solution is needed for a large bed sheet and that is like mixing 40 small bottles! It is best to think differently about mixing up the formula, and use volume measurements instead.
Potassium ferricyanide is much heavier than ferric ammonium citrate so a much smaller volume is needed of it. Given equal weights, ferric ammonium citrate is about 3× the volume of potassium ferricyanide, or, said another way, potassium ferricyanide is about ⅓ the volume of ferric ammonium citrate. It’s not quite this tidy, but it is close enough. If you’ve read the Classic Cyanotype chapter you will by now know how forgiving the formulas are, and how you could almost throw together a handful each of the two chemicals into a bucket of water and it will result in a great fabric print. However, consistency is always a good idea so you know how to repeat what great results you’ve gotten.
A lot of people store single-solution mixes to sensitize fabric. The formula below can be done either way, kept in separate containers or combined into one solution, and it can easily be quadrupled to make half a gallon of sensitizer. One-solution formulas will last for months. This formula gives a range of FAC:PF from 10% FAC:10% PF to 20% FAC:10% PF. As said in the Classic Cyanotype chapter, a 10% FAC:10% PF is faster than a 20% FAC:10% PF and plenty dark; it happens to be my favorite ratio.
Mix one cup of this formula for every yard of fabric.7 The solution will last up to 6 months just fine8, stored cool and dark. Test a long-stored solution on a small piece of fabric before sensitizing larger pieces. Fabric is best if coated, dried, and exposed within the week; otherwise highlights may fog.
25–50 g/6–12 tablespoons/⅓–¾ cup ferric ammonium citrate
250 ml/8 oz/1 cup distilled water
25 g/2 tablespoons potassium ferricyanide
250 ml/8 oz/1 cup distilled water
1. Measure out the ferric ammonium citrate and add it to the 250 ml water and stir until dissolved. FAC goes into solution right away.
2. In a separate container add the potassium ferricyanide to another 250 ml water and stir until dissolved. PF takes a bit of stirring to go into solution, so make sure it is completely dissolved before dipping fabric in it.
3. Either combine both solutions into one or keep the solutions separate and at time of use combine them in equal proportions.
Caution: wear gloves while coating, and do not touch fingers to the fabric because the skin oils will leave fingerprints.
If the fabric pieces are small, there is no difference coating fabric than coating paper. Both can be done with a brush. However, the solution may soak through the cloth and stain the table, so protect the table with glass, Plexiglas, or even plastic garbage bags. If the fabric is wrinkled, iron before brush-coating.
With larger pieces of fabric too big to table coat, better to soak them in a bucket of solution, wring out excess, and hang with clothespins on a clothesline to dry. It’d be great to do this at night in a garage, with plastic bags on the floor to catch the drips.
When hanging fabric to dry, hang it from all four sides so that it dries evenly and the solution doesn’t drip to the bottom of the piece of cloth and result in an uneven coating.9 This is especially necessary for silk. Once the coating is dry the fabric can be ironed and stored in light-safe plastic bags.
Exposing fabric is similar to exposing paper, but can take longer than paper, especially if the fabric is heavy and has absorbed a lot of emulsion.10 Expose some small test strips and test times first. Exposure times can range as short as 5 minutes in direct summer sun to as long as an hour at other times and seasons. Test exposures outside starting at 5 minutes and every 5 minutes thereafter for a total exposure time of one hour. Silk exposes in minimum time, cotton sheeting average time, and cotton t-shirts maximum time. Press the fabric with an iron before exposing if there are wrinkles.
Processing fabric is the same as processing paper, with a first acidified water wash of several minutes followed by a final water wash for a total of 10–15 minutes’ wet immersion. In the second water wash a glug of hydrogen peroxide can be added to hasten oxidation and darken the blues. For small pieces of fabric, a liter of acidified water is plenty. For large fabric pieces, make a bucketful.
60 ml white vinegar (¼ cup) or 2.5 g/½ teaspoon citric acid
1000 ml/1 liter water
1. Add the vinegar or the citric acid to a liter of warm water and stir until evenly dispersed.
2. Remove the fabric from the exposure frame or out from under the glass and immerse the whole of the fabric at once in the acidified warm water.
3. Agitate the fabric continuously in the tray for 1–5 minutes; the water will turn blue, depending on how much wash off occurs.
4. At the end of 1–5 minutes transfer the fabric to another tray of warm water for 5 minutes, and wiggle intermittently to prevent airbells.
5. At the end of another 5 minutes discard the water and refill the tray with warm tap water again. Soak the fabric for another 5 minutes and wiggle the print intermittently to prevent airbells.
6. Once the fabric has gone through a total of 3 washings/15 minutes, it is probably done. Hang the fabric to dry. There should be little to no blue running off of it.
Toning is as simple for fabric as it is for paper, so all the formulas in the Toning Cyanotype chapter will work, but in larger quantities if toning larger pieces of fabric. A mere bucket of water with a tablespoon of Arm & Hammer washing soda or TSP11 will bleach the fabric, and then a bucket of strong brewed tea (depending on how much fabric, 10 tea bags to a liter of water steeped for at least 10 minutes) will tone. Having tannic acid on hand is so much easier than brewing large quantities of tea, so do yourself a favor and buy a pound of it. ½ cup of tannic acid powder to a gallon of water is enough to tone a couple yards of fabric.12
You have to be very careful with washing cyanotype; any alkaline detergents or phosphates in the detergent will bleach the cyanotype to yellow. Test every detergent before using, because once the yellow happens, you can’t get all the blue back even with an acid wash. However, you could tone it to brown if desired.
• Cyanotype-safe soaps are Dove, Ivory, Joy, and Palmolive, and liquid laundry soaps such as Clout, Tide, Wisk, and Woolite.13 Use less detergent, under ¼ cup for a large load, or even a mere half teaspoon in a sink to wash one shirt.14
• For stains, RIT puts out a Stain and Grease Remover No. 90 that works.15
• Silk should not be washed with soap, merely rinsed in a few changes of water acidified with a little lemon juice.
• Don’t just use white or natural cloth; use patterned cloth, colored cloth, etc.
• Boiling fabrics is a great way to get rid of fabric sizing.16
• Keep fingers off the material; fingerprints leave their mark.
• Coating fabric is easiest if you soak it in the solution, but if the fabric is bulky, thick, and stiff, you can also apply the solution with a foam applicator, brush, or sponge.
• When doing fabric photograms, get a large piece of cardboard and put the fabric on top and then pin everything to it. Or, polystyrene foam or insulation board can be used and pinned to with sequin and bead pins from the sewing store.17
• If the design elements are not in direct/flat contact with the fabric it’ll produce a “ghosted” edge which can be quite beautiful.18
• Fabric takes 5× as much solution and exposure times are longer.19
• To create a makeshift light-tight bag to store fabric, wrap it in plastic and then aluminum foil.20
• If a fabric image fades, put it in the dark, give it a hydrogen peroxide rinse,21 or soak it in diluted vinegar.
If coating fabric seems like too much work and mess, there are places that sell pre-coated fabric: Jacquard Products (jacquardproducts.com), Blueprints on Fabric (blueprintsonfabric.com), and the Cyanotype Store (cyanotypestore.com).
Printing cyanotype on glass is much trickier than printing it on fabric; fabric is absorbent, glass is not, and the surface has to be carefully cleaned, subbed with gelatin, coated with sensitizer, and processed in such a way that the solution will stay adhered to the glass and not frill or peel off. If I know anything about printing on glass it is from Galina Manikova (see the Contemporary Cyanotype Artists chapter) whom I “met” on the alternative processes listserv. Much of the following Manikova graciously shared with me via email.
Purchase glass from any glass store and have them sand all edges for you. Otherwise you can use an Arkansas stone (a whetstone found at hunting supply stores) and abrade all edges, top edges, bottom edges, and then directly along the outer edges—perpendicular. This provides a tooth for the edge of the coating material to adhere to as well as prevents cuts.
This should be done extremely carefully. Although many first clean the glass with detergent and water, Manikova has dispensed with this step because the alkalinity of detergents can wreak havoc with cyanotype further down the road.
1. Make a pumice out of whiting powder and rubbing alcohol or methylated alcohol and scrub the glass well (this is what Manikova uses). You can also use Bon Ami glass cleaner, a mild pumice that will not scratch the glass but will remove any silicone coating that the manufacturer might have put on the glass for shipment. Alternatively, you can make your own pumice mix of equal parts Rottenstone (a ground up rock grit finer than pumice), denatured alcohol and distilled water, and put it in a squirty bottle. Shake before use.22 Squirt this mixture on the glass and use dry, soft, lint-free cotton cloths such as old t-shirts, three in succession, to first polish the glass aggressively, then remove the cleaner, and then buff the glass dry. To verify that the glass is clean, breathe on the surface of the glass and examine the fogged glass for any streaks or imperfections. Any grit, no matter how small, must be removed or it will cause the coating to wash off or mar the final image.
2. Take rubbing alcohol, methylated alcohol, or Everclear and clean the glass completely of any remaining dirt, grit, grease, or fingerprints and let dry for 2–3 minutes before one last brush off of any remaining lint, dust, etc., before coating. Note that this whole time, hands should be free of grease, hand cream, etc., and the surface of the glass not marred with fingerprints.
Manikova says, “The thinner the gelatin coating, the better. It needs to be free of any bubbles. If one makes many thin layers by coating in different directions, all the small imperfections and small holes will be eliminated, dissolved and covered by the next layer of thin gelatin. Both room temperature, air humidity and even the mood of the person at that particular moment of time will influence the results. This demands a lot of patience and understanding of the goal.”
1. Add 30–60 g gelatin to 1 liter of cold water (3–6%). Let the gelatin bloom in the water a bit, and then heat until the gelatin is dissolved, to about 140°F.
2. Warm the cleaned glass plate. When warm, pour a first coat of gelatin on the glass and let it cover the glass plate and drip off the edges. Let dry.
3. If the gelatin solution has cooled, heat it again, and coat the glass plate with another layer of gelatin in a different direction. Let dry.
4. Do the same one more time with a third layer of gelatin.
5. Some add formalin to the gelatin in the amount of 5% of the total coating amount. Some add 3 ml glyoxal 40% per 100 ml gelatin.24 This hardens the gelatin layer. Manikova uses a separate formalin bath because once you add formalin to the gelatin you cannot reuse the gelatin.
6. Once the plates are coated, place them on a cold horizontal slab to cool, and as soon as the gelatin sets up, let the glass dry. Manikova notes that gelatin takes about a month to harden. “If the gelatin coat is fresh, it might slide off or water might find its way under the coating during development. Hence, making the coated plates long before use is important. Drying everything properly leveled is also important, unless you dry it in a vertical position and turn around for each new coating. The room should be dust free as possible and with good ventilation. It can be done outside as well, if the weather allows. There is no need to do this part in the darkroom. It is worth building a drying closet for this part, easily made of old cardboard boxes or similar as one needs to let them sit there for about a month.”
Coating the glass plate with cyanotype
Everything is to be held warm: glass plate, gelatin/cyanotype, even brushes, if you are using them. Add the 3–6% gelatin solution to the cyanotype solution in the proportion of 1 part gelatin to 2 parts cyanotype. The gelatin makes it adhere well to the gelatin layer on the glass and also makes it hardier during development. Let it dry.
Greater exposure is required on glass than on paper to get the translucent image to have enough density. Try 45 minutes for classic cyanotype.
Development is in acidified cold water so that the gelatin does not soften. No running water! Manikova says, “I usually just place a plate carefully into the bath with cold water, without moving it too much. I take out the plate before changing the water and placing the plate back into a new water bath carefully. The last water bath is acidic. Then oxidizing by air and fixing in the sun works more gently, and should never be forgotten.
“If everything is done properly there will be no need for an acrylic after coating. I like the surface of the gelatin/emulsion mixture much better. If done right, it will be very strong and scratch resistant after about a month of drying in a dry and hot atmosphere. It will not be sensitive to humidity after that. It can be even washed in cold water if it gets dusty. One can also make a citric bath to freshen them up once in a while, if fading occurs. It takes another month to harden the final print, but after that it sits very well on the glass, and it will be not easy to wash it away, not even with hot water and a scrub. Otherwise I find it very satisfying that any unsuccessful print can be easily removed using hot water, and the glass plate can be used again.”
Cyanotype can be printed directly onto Pictorico OHP transparency film to make a sort of “poor man’s” glass print or lantern slide. The OHP has a layer of ceramic coating that absorbs the solution well with no bleeding or smearing.25 When initially coating, the ceramic will grab onto the solution and leave a white mark, but keep brushing thinly until it evens out. Lift it vertically and from all four sides so the solution runs down (watch holding it because it is slippery!). If the OHP is laid down flat it will puddle and be ruined. Expose and process as you would a normal print; new cyanotype looked great at 7 minutes and overexposure produces a somewhat odd shimmery purple on the surface.
Wood is a breeze compared to glass but brings its own set of problems. For one, the cyanotype solution will sink into the wood and stain it, so therefore it is best to size the wood with gelatin or PVA. Two, the highlights of the image are no lighter than the wood itself, so take that into consideration.
Michaels or other craft stores sell birch plywood pieces and birch is quite light with minimal wood grain so that might be your best bet for a first foray.
Check the wood for imperfections before buying. There are also cradled wood panels in birch or basswood that come attached to the frame and they are smooth and sanded. They are reasonably priced.
1. If the edges of the wood are splintery, sand them smooth.
2. Clean the wood thoroughly with plain water and let it dry completely.
3. Size with Gamblin PVA full strength, two coats, or use gelatin: add 30–60 g gelatin to a liter of cold water and let the gelatin bloom for 10 minutes.
4. Heat the gelatin and water slowly until it reaches around 140°F or thereabouts. No need to be exact.
5. Brush the wood with the warm gelatin in a thin coat and let the gelatin dry thoroughly.
6. Coat the wood with either the plain cyanotype solution or a gelatin/cyanotype solution, up to 1 part gelatin to 3 parts cyanotype. Let the layer dry thoroughly.
7. Expose and process the wood print as normal, but err on the side of overexposure and longer development because wood is absorbent and you want to make sure to remove any iron salts so the print doesn’t fog with time.
Endnotes
1. Brown, Ruth. Cyanotypes on Fabric. A blueprint on how to produce…blueprints! East Yorkshire: SC Publications, 2016, p. 13.
2. Ibid., p. 12.
3. Ibid.
4. Ibid; Fabbri, Malin and Gary. Blueprint to Cyanotypes. Alternativephotography.com, 2006, p. 42.
5. Brown, p. 78.
6. Hewitt, Barbara. Blueprints on Fabric, Innovative Uses for Cyanotype. Loveland, Colorado: Interweave Press, Inc., 1995, pp. 19–20.
7. Hewitt, pp. 21, 24; Brown, p. 17.
8. Hewitt, pp. 27–28.
9. Newman, Thelma R. Innovative Printmaking, The Making of Two- and Three-Dimensional Prints and Multiples. New York: Crown Publishers, 1977, p. 114.
10. Hewitt, p. 53.
11. Ibid., p. 65.
12. Ibid., p. 67.
13. Ibid., p. 68
14. Ibid., p. 69.
15. Ibid., p. 94.
16. Howell-Koehler, Nancy. Photo Art Processes. Worcester, Massachusetts: Davis Publishing Inc., 1980, p. 67.
17. Brown, p. 32.
18. Ibid, p. 31.
19. Antonini, Marco, Sergio Minniti, Francisco Gomez, Gabriele Lungarella, and Luca Bendandi. Experimental Photography: A Handbook of Techniques. New York: Thames & Hudson, Inc., 2015, pp. 136–145, 206–207.
20. Brown, p. 23.
21. Brown, p. 78.
22. Mark Andrews on the alt list.
23. An APUG thread talks about Kuraray R-1110 silated 100% hydrolyzed PVA, which you coat on glass and dry overnight, then bake for 30 minutes (250°F) and let cool. The cyanotype print is then coated, exposed, and processed as normal. After processing and drying, the plate is again baked for 10 minutes. The product is mixed in a 10% solution and heated to 200°F to get it to dissolve. See www.kuraray-am.com. Others coat the cleaned glass with a layer of Silane Glass Treatment, available from Bostick & Sullivan.
24. James, Christopher. The Book of Alternative Photographic Processes. New York: Delmar Cengage, 2016, pp. 220–222.
25. Ware, Mike. Cyanomicon II, History, Science and Art of Cyanotype: photographic printing in Prussian blue. Buxton: self-published, 2016, pp. 102–103. http://www.mikeware.co.uk/mikeware/downloads.html