Red Tulip part II

The two red tulip anthotypes were exposed for about the same amount of time. I estimate about nine days give or take a rain day. 

If you look at the lower right corner you can see rain did make its presence known despite wrapping the "contraption" in plastic. The contraption is usually a thin sheet of OSB, the paper coated with pigment, the garment, and Plexiglass all held together by spring clamps. The spring clamps show up occasionally around the periphery of the finished anthotype. Bridgette has described them as giving the finished piece a rhythm. I use to hate the artifacts they left behind, now I am kind of digging them. 

This anthotype was made with the same emulsion as the "Little Gown" anthotype but I kept the red tulip color by adding a bit of citric acid to the emulsion. Normally this paper (Arches Cover) and Fabriano Artistico have a bit of buffer that pushes the color to the blue end of the spectrum. Flower pigments act as a pH indicator for naturalists. I have even made purple iris pigment red. 

This is "Red Tulip (acidic) Peignoir #1". 51" (H) x 42" (w).

Speaking of iris pigment. I raided the last ones today. I have a bit frozen away and two sheets already coated one of which is exposing right now. I see plenty of purple gowns, peignoirs and pajamas in the future.

Experiments from the Garden of Roses, Part II

Anthotype science. I like this kind of stuff.

The rose petal extract demonstrates a classic pH indicator color change. I wish I had a pH meter to compare my guesses but for now these estimates will have to do. I noticed that when I washed out anything that had been in contact with crushed red rose petals, it would turn the water blue which would be around pH 7. Last week when I suspected the leftover rose petal extract was oxidizing to a brown, I added a classic food preservative, citric acid, to the fresh rose petal emulsion. It went from a cool red (pink red) to a warm red (crimson). Yesterday evening I again added citric acid to the latest batch of red rose petal emulsion and saw the warm red effect. In washing out one of the beakers I created about 3oo cc of faintly blue water into which I added a pinch of citric acid. It shifted the water to a faint red before it went clear. Now the question is, what was the pH of the pinch of citric acid in water that I created? Probably pH 4-5.

In creating some green Anthotype emulsion from grass, I noticed that adding citric acid created more of a brown green or olive color and possibly contributed to flocculation. For the grass I am probably going to just use distilled water and crushed leaves (blades). As of yesterday, the sheet of paper I have coated has about 5 coats of green applied to it.

Pictures soon. Of immediate concern is tracking down some coffee this morning.

paper matters

The one variable that strikes fear into the hearts of those of us working with hand applied, light sensitive emulsions: paper types and paper pH. With a delicate, hard to harvest and distill emulsion like the purple flowers I am discovering that paper matters.

I've been noticing that the flower petal emulsion seems a bit faint and much bluer than I expected. I've come across references to flower pigments yielding surprise colors with no reason. I suspect that the pH of the paper is the culprit.

The picture above has four paper types.

1. The paper on the bottom is the Fabriano Aritstico Hot Press Extra White. It worked great for the Pokeberry juice but the emulsion seems faint when brushing on. I ended up putting three coats on it and got what Bridgette thinks is a nice blue. Thanks Bridgette and Jill for the suggestion.
2. The next paper is a light weight Kozo paper from Bostick and Sullivan. It was labeled E on their old sampler pack which was a freebie a few years back!
3. On top of that is a square of Arches Platine, a favorite paper of platinum palladium printers.
4. On top of everything is a strip of my favorite Kozo Unryu (the backside). Surprise... it looks the best!

BTW, the happy accident also contributed to this report. I was using the Kozo Unryu as a means of wiping off the organic debris from my brush and noticed that it looked purple and the purple seemed stronger than the blue that was applied in one coat to the Fabriano. I don't know the pH of the Kozo Unryu but I do know the Kozo light weight and Arches Platine work well with iron (siderotype) processes because of their neutral to slightly acidic pH.

I remember from undergraduate biochemistry the role of pH on the 3-D structure of proteins. During the last few weeks  also discovered that heating plant pigments to "reduce" them is not a good idea. I lost the rich magenta color of pokeberrry doing this very thing. Changing the shape of the protein via heat  or pH may change its color.