Sunday, April 9, 2017

Metal Stencils

Jean Saudé was the first to write instructions on how to do pochoir. In his 1925 book, Traité d’enluminaire d’art au pochoir, he gave a brief overview of the history of pochoir, explained the techniques which were accompanied by drawings, and showed examples, including several progressives. They used metal stencils, copper, tin, pewter, aluminum or zinc, in varying thickness. The knife could be straight or slightly curved, and they used linoleum as the cutting mat under the plate. You will find a link to Saudé’s magnificent, intricate copper stencil in my March color blog.

I had been taught to use acetate stencils with a dry brush in 1988.  I just learned that the Letterform Archive is publishing a new book on William Addison Dwiggins, which explains how he used that technique in 1928 for his variable design elements. I took the time to translate the Saudé book into English so that I might understand the cutting of the metal stencils, a few months before Havilah Press came out with an English edition. But it still wasn’t entirely clear how to cut the metal stencils.

I received a faculty research grant from Scripps College in 2015 to travel to Paris for a month to research why La Prose had not been completed. I did research at the Bibliothèque Nationale, Bibliothèque Fornay, and the Jacques Doucet Library, and I took the train over to the Tate Modern in London to see the blockbuster Sonia Delaunay retrospective. I had found Atelier Coloris online through an article by Zwartkruis online and now wrote to them, asking if I could visit them in Ploubazlanec, France. I spent a glorious week learning how to cut the metal stencils and use the brush in the traditional way.

Nathalie Couderc and Christine Menguy work together on pochoir projects at Atelier Coloris, and Christine also runs a framing atelier in the same building. They had worked together at the famous pochoir atelier, Daniel Jacomet, for five years. Nathalie agreed to work with me for a daily fee. It was thrilling to be there, amongst the stencils and brushes that she used every day.

Nathalie Couderc with Kitty at Atelier Coloris

 The very first task is to study carefully the image that you are reproducing by pochoir. You will need to separate the colors and decide which colors to use first, usually light to dark. Our model was the Yale facsimile, but we also had my photos from the Getty copy and the online version from the British Library. I had already studied the colors and made tracings earlier, but now we decided on which color to start with, the light green. We set up the first registration system by marking the corners of the page on the tracing paper. Then I traced the light green areas.

Tracing the light green areas on the glued but unfolded Yale facsimile given to Kitty by Timothy Young at Yale

 Next you tape the tracing onto the plate, which was .0055” aluminum, an offset printing plate by AGFA. The knife that Nathalie used was given to her by her pochoir master, so I felt I couldn’t use that. Her knife was slightly curved and was held in a round metal ferrule so that you can rotate while cutting. Naturally it needed sharpening as you went along. 

Nathalie showing how to cut the aluminum plate

 I had brought an Olfa knife with changeable blades, and that worked well enough. It has a very sturdy blade that doesn’t bend much while cutting.

Olfa knife with changeable blades compared to Nathalie’s knife

Under the aluminum was a rubber mat. Nathalie gave me a piece to take home, and I just found out what it is: 65 durometer solid neoprene rubber. The normal cutting mats we use are too hard, as the knife has to plunge into the rubber just so. 

Rubber mat, 65 durometer, solid neoprene rubber, one-half inch thick

You hold the knife normally, but you place your index finger (or sometimes middle finger) of the left hand onto the ferrule to help push the blade along. So the action is: plunge through the tracing and plate, push with the left hand and drag with the right all at once, and plunge again. Slowly you work along the pencil line you drew. It works more easily if you push the tip into some pig fat (I use bacon fat at home now, kept in the freezer).

The result is a series of short cuts that need to be flattened. The following short video demonstrates the cutting technique:

Cuts into the aluminum plate

 We used a wine bottle filled with lead shot and rolled it over the cut areas on both sides. This is done on a marble base, using full body weight. 

Flattening the cuts on a stencil using a wine bottle filled with lead shot

Now you are ready to pochoir. You want to be in natural light coming from the north, since you want to make sure your colors are matching your original. The gouache colors are mixed in a bottle to the consistency of skim milk. For an edition of five, as I was doing, you don’t need to make very much, but normally a half-bottle would be mixed. You choose a brush that had earlier used a similar color and was the right size for the stencil hole. 

The hog-bristle pochoir brushes are grouped by color

Place some gouache from the bottle into a plate and swirl around the brush to activate it. Now the challenge is to have exactly the right amount of moisture in the brush each time to do an edition, and to have them all look the same. In the photo, I am practicing the new darker green color before I work on the edition, which you can see near the window. 

Practising pochoiring the darker green area

 The registration scheme is as follows: after the first stencil where you marked the corners of the paper, on the second stencil you trace several areas that you just stenciled for registration positions. It’s best to have two or three areas for position. Those areas are cut out and are taped with scotch tape on both sides. You can see one of the areas in the upper left corner of the plate in the photo. The third plate then is registered to the second plate, and so on.

One of the most vexing problems while stenciling with acetate is that the color can easily seep under the edge of the hole, and that is the main reason for the dry brush. So I was really curious how that would be solved at Atelier Coloris when using metal stencils, which have the same problem, and a wet brush. Their solution was to put a little pig fat on the edges of the cut-out on the reverse, about 1/16” in from the edge, which is then brushed with a dedicated brush to even it out. Since grease repels water, it minimizes the problem, but you still have to be quite vigilant and choose an appropriate paper. You also need a very light touch.

Many of the 15 color areas on page one had special effects, some of which puzzled Nathalie and Christine, particularly the half-moon area. We decided to have four different colors in this area, but then use a small flat brush once the stencil was off to blend two areas.  

Brushing the half-moon area to blend colors, plate removed

This was not entirely successful, so I will be explaining next time about the many special effects we figured out how to do last month when I was making my most recent edition of 182 copies for the Zamorano Club, for a talk on April 5, 2017.

It was rewarding to have been able to cut all 15 of the stencils and to do the pochoiring myself, under the supervision of Nathalie and Christine. I made an edition of five copies and let them choose which one they wanted to keep.

Nathalie and Christine holding the completed facsimile of page one