One thing that goes with this territory of building and maintaining dioramas is that sometimes things don’t go as smoothly as you’d like.  I am now running into this with the leaf making.  Here is a list of the problems as they stand right now:

1. Ken had difficulty creating a matrix on the scanned mold.  I have to see if he can come up with another way to do this. If there is not an easy way, my prints won’t fit well into the molds.

2. I experimented with the opaque white Inkaid substrate and found that the 50-50 and 75-25 mixes with transparent substrate were too thin to get good saturated color.  I airbrushed full strength white substrate and even that didn’t give me the saturation I got in the fabric.  It might be that fabric absorbs more color into the weave and therefore is innately more saturated than acetate. I will spray out a double coat of the white and see what I get.  The single layer of white still gives me adequate translucency.

fabric on top, acetate on bottom.  The photo doesn't show the lesser saturation on the acetate as well as in life.

fabric on top, acetate on bottom. The photo doesn’t show the lesser saturation of the acetate as it actually is.


3. There is not as much strength in the vacuforming as I had wanted and this is because of problems I am having with the 10 mil acetate and the need to do one leaf at a time. If I use a heat gun on the printed acetate, the ink discolors or burns easily.  You have to be very careful for this not to happen.  I found that if I cut the leaf to the contours dictated by the print, lay it down and register it on the mold, cover it with a larger piece of acetate and heat all of it, I can get good suction and a leaf with good contours, but not with the veins and subtle detail.  The lack of full saturation of color is not going to derail this, but if I can’t figure out a way to get better detail, I’m not sure I will find this method as workable as I’d hoped.  I guess I could let the print give a 2D representation of the detail, but I want the form of the leaf to show it too.

Vacuforming method for single leaves.

Vacuforming method for single leaves.

4. The non-print side needs attention because it is white.

So, there are a lot of things to consider before this is really ready to go into production. Stay tuned!


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More Printing on Acetate

Leaf mold to be scanned

Leaf mold to be scanned

I dropped off a leaf mold today at Ken Lovell’s lab (Yale Digital Media Center for the Arts).  He is going to make a 3D scan of the surface of the mold, create a matrix that will be laid over the prints of the leaves.   From this, he will morph the prints so they should vacuform right down onto the mold perfectly.  As Ken said, in theory!  I haven’t had a chance yet to use a milky subsurface on the acetate that will run through the inkjet printer.

Pabric with printed leaves

Pabric with printed leaves

One other note, I purchased some “Pabric” fabric that can be run through the inkjet printer.  I made a test and wasn’t happy with the saturation of the color in the fabric (not saturated enough) or the ability to glue it to the vacuform leaf (the material is too heavy).  The fabric printing still is a strong plan B.  Ken mentioned today that he can get a printable polysilk (cheaply) that can also be run through the printer.  The only problem with doing it with fabric is I lose some or all of the detail of the form of the leaf  I can get with the vacuforming.

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Printing on 10 mil Vacuforming Acetate (PETG)

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.

Leaf prints on PETG.  Color saturation good with white background.

Leaf prints on 11X17 PETG. Color saturation good with white background.

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!

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American Museum of Natural History Visit

George Petersen circa 1950s, Plant fabricator extraordinaire.

George Petersen circa 1950s, Plant fabricator extraordinaire.

Autumn and I took the train down to the American Museum of Natural History (AMNH) to meet with their vacuform specialist, Beck Meah.  We brought a couple of our printed vacuform leaves to show her what we are doing.  We met her on the fifth floor of the Exhibition Department where the vacuform machine is located and got to “talk shop” for about an hour.  The AMNH’s vacuform machine has a defective vacuum pump and they have rigged it up temporarily with a regular shop vac.  Surprisingly, they seem to be getting good results with it!  They use clear Vivak and sometimes a thin white (opaque) styrene instead of acetate or PETG.  Beck said they bought a large amount of the Vivak years ago.  She gave me a sample to try back at the Peabody.  I put a vernier caliper on it and it is thinner by half! of what I am using.  The PETG I use is .020” and the Vivak is .010”.  She said that they are looking for a good glue to adhere the leaves to the wires, which is a problem I have, as well.  I use B-72 and the results are less than satisfactory.  Beck said they sometimes drill two small holes in the vein and snake the wire up and through the two holes to hold it mechanically rather than depend on the glue.  She also said that in some of the dioramas the preparators would wire the leaves on top of the leaf if it was going to be seen from below to help hide the wire.  We will use that advice when we make the maple leaves for Forest Margin diorama for that very reason.  They will be seen from below.  Beck uses extrinsic painting on the leaves and says that she can get an acceptable translucency by keeping the paint application light.  I believe her because Tomy Newberry and Gary Hoyle, two preparators I have great respect for, both said the same thing to me.  That said, I have found that any paint on the surface reduces the translucency and I am sure the old-timers knew this and struggled with it as well.  I walked through the African biodiversity exhibit, which opened ten years ago or so to assess some of the more recent leaf work.  I found the leaves to be mostly opaque which therefore gives them (now that I have been mentored by Ray deLucia) an unsatisfactory plasticky look.  The form was good because they were vacuformed, but the realism was lost to some extent because of the opacity.

At the AMNH, they make plants by soldering together brass branches and adhering the leaves afterwards.  I learned to make plants by making the leaves and gluing on the petiole, or leaf stems, first and then wiring them together afterwards using shrink tubing and epoxy glue, building the plant from the top down, adding more leaves and branches as I go down. With this method, I get rather lumpy branches that need attention to get them to look realiastic.  This other way might save time.  Beck said that there is a soldering tool sold at Micro Mark that can solder small brass wires to thicker stems with just a tiny bit of solder.    That sounds like a useful tool to have around.  This is why I love to talk to other museum preparators!

Tomas Newberry, circa 1957, Foreground of the Redwood diorama.

Tomas Newberry, circa 1957, Foreground of the Redwood diorama.

Autumn and I left Beck and walked down to the Olympic Rainforest diorama to look at the leaves done in the early 1950s by the legendary foreground preparators, George Petersen, Fred Jalayer, and Tomy Newberry.  We were blown away at the attention to detail, the translucency, and the realism everywhere we looked.  This level of quality probably can’t be recreated today.  George Petersen made leaves for his whole career at the AMNH.  Forty years of honing one’s skills just on leafmaking is hard to match by us generalists!

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The Quest Goes On-Maple Leaves

I am working now with Autumn Von Plinsky, a recent Yale Art School grad, on this project and this week we got another type of leaf produced, a maple leaf.

Sugar maple I

There are still some problems, but there is a lot that is working well.  First, the problems:  The detail of the leaf is compromised by the printed fabric, but only if it is adhered to the bottom of the leaf, and also by the wax coating.  This method sacrifices some of the surface detail of the veins and subtle texture of the leaf for a strong graphic quality.  The excellent surface detail is typically why leaves are vacuformed in the first place.  Another concern is the quality of the ink used in the printing process.  How colorfast will they be?  This will have to be researched before any of the new leaves are placed permanently into the dioramas.  The selling point of this method is that it is fast, there is no need to paint detail, which in this case could take hours, and the leaves are strongly translucent.

Sugar maple II

I have yet to put these leaves into the diorama, but I think they will read well and the graphic quality will carry them.  Ideally, we might be able to develop this to get both the texture and the graphic qualities.

Autumn found out that one of the graduate students in the Yale Graphics Program is printing on acetate and vacuforming over three-dimensional objects.  There is going to be a presentation about this method on Nov 8th.  We will be attending with the hope that we might be able to use this process to vacuform printed acetate leaves on our plaster leaf molds.  If this works we might be able to achieve a leaf that is quick to make and has the subtle texture of a real leaf.

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AMNH visit

I went down to look at the exhibits in the American Museum yesterday.  I focused on the Warburg Hall (1951) and the North American Hall of Forests (1959) to see some of the work of the really great foreground artists from the 1950′s, guys like Tomy Newberry, Fred Scherer, George Petersen, and Fred Jalayer.   Newberry is still alive and I talked with him on the phone last week.  I mentioned that I was really impressed by the work I saw in the Warburg Hall, mentioning specifically the lady sliper flowers.   This summer, I walked through the hall with a retired educator, Bill Schiller, who pointed out that the flowers were so accurate, that he could teach schoolkids about how pollen gets stuck to the back of bees when they crawl into the flower.  He can show the flower structure that does this from the model.


Newberry said that they were quite dedicated to the work.  They pushed each other to do good work, even to try to outdo one another.  Here are some maple leaves from the Olympic Forest diorama.  These are exactly what I am trying to get with my quest for translucency in leaf fabrication.  I hope they are not made from paper, because I think it is only a matter of time before they will start to curl.:



I also saw some work that was of very high quality, but made with paper and starting to curl with age.  The Warburg Hall and the NA Hall of Forests are long overdo for a cleaning and renovation.  Unfortunately, they will probably be torn out at some point in the near future.

Beautiful work, but look closely at some of the leaves.  They are curling up.

Beautiful work, but look closely at some of the leaves. They are curling up.

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Translucent Leaves: Ready for Prime Time

Poly silk print on vacufom leave.  Colored wax over all.

Poly silk print on vacufom leave. Colored wax over all.

Using a print on “Poly Silk” adhered to the vacuform leaf works very well (Thank you Sally Pallatto for the idea!).  I use a dilute solution of B72 to wet the poly silk and it conforms almost on its own.  The fabric adheres to almost all of the curves and forms of the vacuform leaf.  I found that it works better with less air bubbles if I adhere it to the top side of the vacuform leaf rather than to the side with the impression of the veins.  After the glue dries, I dip the vacuform leaf with print into colored beeswax, shaking off the excess wax.  I’m going to do more tests on this method, but I am close to being ready to make a large run now.

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