Blogging for Thor: Going Green

An anthotype works by using natural pigments that break down under light. Where your pigment is protected from light, it remains dark; where it is exposed to light, it fades to a paler shade. This creates a positive image. Normally anthotypes are made by taking these pigments out of their natural source, purifying them, and applying them to a substrate. That isn't technically necessary. One of the early ancestors of the anthotype process was a technique popular in 19th century France where fruit intended for table settings was placed in sunlight behind intricately cut stencils. The stencils would shape the light, and the surface of the fruit would fade, producing patterned surfaces.

Sweet Potato Vine leaf imprinted on a Hosta Leaf

So, really, there's not a need to remove the pigment from its original source. That idea has been developed to extremely high levels by artists like Binh Danh, who his process a chlorophyll print. What he does is take a leaf (or many leaves) and places a negative on top of them. The sunlight breaks down the chlorophyll in the leaf (only works if the leaf is removed from the tree, obviously) and you end up with the green color preserved where the light was blocked; everywhere else the leaf fades and turns pale creamy yellow.

Chlorophyll printing is a cool, fun process. It actually tends to be pretty fast for an anthotype process; it prints in just a few hours if you use the right kind of leaf. If you use the wrong kind of leaf, it can take days and hardly show up at all. So far I've only tried a few kinds of leaves and my best results are from big, thin leaves like hosta and caladium. Thicker, fuzzier leaves don't tend to fade as well. It can record detail very nicely. I've been able to see some pretty decent tonal range in the leaf prints, but the results are more dramatic with strong contrast and easily identified shapes. If your negative relies heavily on subtle textures and delicate shading, it probably won't return a great result. You are, after all, not dealing with a traditional photo-sensitive metal salt process.

Chlorophyll prints are something I plan to experiment with further. I really like Danh's idea of using multiple blades of grass together as a mat to create a large area for exposure. He preserves his chlorophyll prints by casting them in clear resin. I have no idea how that would affect fading, since the resin is still transparent. Then again, I have no idea how archival the chlorophyll prints are in the first place. Dried leaves can keep their color for a fairly long time, after all.

As a final note: I am almost certain this process won't work on evergreen foliage or on autumn leaves or already-dead leaves that have lost all their green. I'm pretty sure the chlorophyll needs to be intact to make this type of print work. Who knows, this fall might prove me wrong!