I think I have finally stumbled upon the way to get what I want with making accurate, translucent leaves. Earlier, I wrote about matching photographs of leaves with plaster molds made from the same leaf and then using inkjet prints of leaves on a scrim fabric with the associated mold to get a good replica (blog entry: July 2013). This was close to perfect except, I went down the wrong track by trying to make vacuform casts from the molds and adhere the fabric to the vacuform leaves. This week, close to the June 15th date of the Shoreline diorama, I went out and collected more red osier from a nearby lake. I photographed the leaves and then made plaster molds, this time, of both the front and back.
From the photographs, Sally made prints off the inkjet printer on a fabric from Jacquard called Habotai 10mm. This fabric is close to a scrim material and therefore the colored print shows through front and back. By the way, I spent a day or so getting accurate color from the actual leaves-both front and back. Sally then printed several leaves with different saturations of different colors. We ultimately found a green that is almost an exact copy of the actual leaves (in daylight).
Five minute epoxy is mixed with a bit of green oil pigment made from ultramarine blue and cadmium yellow light. The epoxy is spread over one side of the mold (light vaseline used on leaf surface, heavier on the periphery) and the fabric tamped down into it making sure the middle vein lines up with the mold’s vein. The second half of the mold (also with vaseline) is given a coating of epoxy and carefully laid over the first half of the mold. A spring clamp compresses the two halves. A good cast is insured when epoxy oozes from the seams. In five minutes, the epoxy is set and the cast can be lifted out.
The cast can be fully removed from the mold immediately or it can rest in the mold for an hour until the epoxy hardens more. The flashing is then cut away with scissors and the result is extremely lifelike! There is no need for any extrinsic painting or waxing. The shininess is controlled by dusting with fumed silica.
I will have two interns working for me over the summer and we are going to go into production. I have one outlying concern. Thin epoxy over time does tend to droop and yellow. The fabric may keep the drooping from happening, but I will be making tests of this and watch for color changes. A tapered wire might need to be cast in along the midline for support.