Photos

Screen Printing with Mordents, Acids, and Alkalis

I had an idea... well more of a need. I wanted to put my logo on my designs without driving my coast of making up, while still keeping the product natural and organic.

I began by burning a screen with the image that I use as my logo, its a mannequin that I have used in my artwork for years named Janice. I have not burned a screen in almost a year. Actually the burning part was not the problem, I didn't coat the screen with the emulsion evenly. I think if I had the product would have come out much better.

After burning the screen I made up three different pastes. I combined a translucent pigment stretcher used primarily in screen printing with an iron mordent, cream of tartar, and soda ash. The iron mordent and the cream of tartar mixed into the water salable clear base easily. The soda ask did not dissolve so easily. I dissolved the soda ash in 4oz. of boiling water before stirring it to the clear bass. Next the soda ash past was spread over a paper to soak up access water.

After paste were mixed, I then printed the three different mixtures onto three different fibers, organic cotton, bamboo fleece, and silk. Making 9 samples total. After printing the samples were left to dry for 30 min. The silk was a heavy twill, I tried it on something lighter but the image would only bleed.

The samples were placed in a madder root dye bath with an alum mordent for 10min.

The image comes out fantastically with out modify the bath too much.

pH Changes in the Dye Bath

This is where I spent the majority of my time. I was completely amazed at the range of color that was produced from simply shifting the pH level of the dye bath to more acidic or alkali.

The Dyes Tested:

Pomegranate

Madder

Osage Orange

Annoto

Brazil Wood

Log Wood

Cutch

Myrobalan

Tannin

pH Shifters Used:

Lemon Juice (pH 3)

Cream of Tarter (pH 3-4)

Baking Soda (pH 8)

Soda Ash (pH 11)

Lye (pH 12-14)

I tested different combination from the listed above on three different fibers.

Bamboo Fleece (Cellulose)

Organic Cotton (Cellulose)

Silk (Protein)

I wanted to see the different affects each combination would have on the different fibers. I also wanted to see how far I could push the protein fibers on the pH scale before they would fall apart. They held up okay till the lye. I did this one with gloves, goggles, and under a fume hood.

Independent Study Projects

My time spent in my Independent Study Chemistry class has been divided into studying three different processes, the first one being subtractive color. I first dyed 8 pieces of silk with 8 different dye recipes.

1. Myrobalan and Alum Sulfate

2. Osage Orange, Alum, and Lemon Juice (dye bath pH 3)

3. Pomegranate, Alum, and Lemon Juice (dye bath pH 3)

4. Madder, Alum, and Lemon Juice (dye bath pH 3)

5. Madder, Alum, and Soda Ash (dye bath pH 10)

6. Pomegranate, Alum and Soda Ash (dye bath pH 10)

7. Cutch, Alum and Soda Ash (dye bath pH 10)

8. Madder, Cutch, Pomegranate, Alum and Soda Ash (dye bath pH 10)

I choose this as my starting point because I have not come up with a satisfying green dye recipe. By dipping the yellow samples in indigo I might find something I like. I also thought it would be a nice time to experiment with some red and orange samples as well. I am still diping to ket my desired color. The coloring in silk is very illusive, it dries anywhere from 2 to 8 shades lighter than its dipped color. Plus silk which is a protein fiber is not a fan of the alkali indigo bath. The pH changes in the dye bath and the effects that it has on both Cellulose and Protein fibers is what lead me to my next project.