I used transparent colored plexi-tubes for these photograms. I put different colored tubes with different diameters into each other, so the light going through all gives a mixture of colors. The interesting thing in this process is the nature of the color mixing. Theoretically the result is always subtractive color mixing on the photo paper. But in fact on the photograms you see examples of additive color mixing. This is a paradox, theoretically impossible situation, the union of the two different ways of color mixing.
There are four fixed running out tubes on each image, besides many smaller pieces of tubes which are randomly placed. The continouos straight lines make possible to form one big picture (700x100 cm).