Embedded Files
This is a hand-drawn, four-color separation lithograph, produced via the process described below.
I took the photograph above in 2006, at the summit of Volcán Poás (Poas Volcano) in Costa Rica. In the four-color separation process, the original image – in this case, this photograph – is digitally separated into four colors: cyan, magenta, yellow, and black (CMYK). The monochromatic image of each color is burned onto a litho plate, and the image is printed in each of the four colors. As the four colors overlap in printing with differing intensities, the resulting print is a full-color image. In this case, I will be hand-drawing the four plates on frosted mylar with a combination of graphite and india ink. These semi-transparent drawings will be exposed to the photo-sensitive litho plates to create the image.
Step 1: digital four-color separation
The small images above are the four layers that create the full color image – when these images are digitally overlaid or printed over one another, they create the full color spectrum. To make the litho plate, however, each image is treated as a monochromatic (i.e. grayscale) image. The image to the left is the greyscale map of the image that will be printed in yellow (Y). Where the image appears darkest, (the underside of the leaf near the center of the image) is where the final image will be heaviest in yellow. As you can see from the full-color image above, there will also be cyan and even a little magenta printed un the leaf, and the resulting color (keep your fingers crossed) will be a deep, earthy green.
Step 2: creating the images on mylar
To create the four separate plates that will print one color on top of the other, everything must be perfectly aligned, or 'registered'. Thus it is necessary to trace the image carefully from the original. Since the photo-exposure process reverses the image, the drawing must be done backwards. Here you see the digital print-out of the greyscale image in magenta. The print-out lays face down on the light table, and the mylar is carefully placed and taped on the back. I first went in with india ink to create the darkest blacks. Then I used graphite (4B, 2B, HB, 2H) to fill in the detail. This image is about 1/4 complete.
Step 3: printing
The four images above are prints of the four plates that were created from the digital separation images above. Each of these images was transfered from the hand-drawn mylar to the litho plate via a photographic exposure process. These plates are printed on top of one another in the order Magenta-Yellow-Cyan-Black to produce the final image:
The final, four-color print was printed on Reeves BFK white paper 6 times:
1. magenta
It was printed on Plike (a plastic "paper-like" imitation) 4 times, the result of which is a more vibrant, saturated image with fewer runs through the press:
2. magenta-yellow
3. magenta-yellow-cyan
And it was printed 3 times on Plike in regular Red-Blue-Yellow-Black inks, rather than the process CMYK colors:
4. magenta-yellow-cyan black
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