I found 10 mil PETG from a company called Sabic Polymershapes. They cut the plastic to my specs so it is ready to use in my vacuform machine. Now, I have what I need to test the printing on the vacuform sheet itself. I also found the material, Vivak, that I was given at the AMNH is also 10 mil PETG.
This Friday, I went to Yale’s Digital Media Center to work with Ken Lovell. Ken demonstrated rolling out a couple of layers of a print-friendly substrate called Inkaid on the PETG, letting it dry, and then, running it through the inkjet printer. The ink from the printer adheres to the Inkaid substrate just like it was paper. Here’s a photo of the results.
I inquired with Inkaid about the archival quality of the material and they assured me that it would last as long as the Epson inks, which are calculated to last for over 100 years! This is very good news for making leaves for the dioramas. I brought the prints back to my lab with the molds. I set up a vacuform box so I can test this process, one leaf at a time.
THE TEST: I was able to pull a pretty good cast, but getting the printed veins to line up with the veins in the mold was almost impossible. I had to try to move the hot acetate into place and had trouble with the plastic folding and sticking to itself. There is just so much the PETG can be moved around while in its melted state. Another problem is that printing on the clear acetate makes the inks appear less saturated. When printing on fabric, the white surface reflects the light back through to color in such a way that the colors appear about twice as saturated as on the plain acetate. This could be a problem, but Ken suggested I try a mixture of clear and white Inkaid substrates to produce a milky surface on which to print. It might be possible to get the same translucency and reflectivity of the fabric. Then, I would have to work on getting the print to line up in the mold. Ken thinks the shape of the 2D prints could be changed to fit the 3D shape of the mold by 3D scanning the molds and using some morphing software he has in the lab.
Ken also suggests I try printing on a subsurface made up of several layers of acrylic gloss medium or matte medium mixed with white acrylic to get a milky translucent “skin”. The acrylic medium is built up, layer-by-layer on a sheet of plastic, covered with another layer of Inkaid and the whole thing is run through the printer. The dried acrylic medium/Inkaid “skin” can then be peeled off the surface of the plastic and adhered to the vacuform leaf. This is esssentially another cheaper version of the fabric printing method. More work to be done!