Discover how to create graded shadows and highlights on collagraph plates, producing 3d and contoured effects in your collagraph prints.
Creating areas of distinct light and dark in collagraphs is fairly straightforward but what if you want to have a graded change from light to dark? How can you achieve this soft effect of tonal change from dark shadows to bright highlights?
In this post I will help you to create more 3d effects in your prints, providing increased depth and interest. It takes a little bit of planning but once you understand the concept you will find it a really useful technique to give sculptural form and substance to your images.
The image shows students work using sandpaper and a circle with a graded shadow effect.
Why would you want to grade your tones?
If your different tones are in distinct areas with sharp edges this will emphasise the flat plane of the image. Grading the tones gradually means you can create convincing spheres, cylinders, mounds, valleys and other curvy shapes with various contours. Using this technique enables you to move from a flat plane of texture and tone, to a more sculptural effect.
Understand one of the basic concepts in collagraph plate making
I drum this mantra into my students on courses;
Shiny areas will print light, rough areas will print dark.
It is one of the key things to ‘get’ when you are making collagraph plates. When you ink your plate as intaglio you rub the ink into the textures on the surface and then wipe it off the top levels.
The indentations will hold ink, as will any rough areas of texture. Imagine spreading sticky printing ink onto sandpaper and then trying to wipe it clean – this is impossible. The rough sandpaper grips the ink and therefore will print as a dark area.
However if you have smooth shiny areas on your plate, for instance Sellotape or aluminium tape it is easy to wipe all the ink off; with very little ink on them these will print as light areas.
Make a test plate
Here is a practice exercise, I’d suggest doing this first to get the general idea. It is easiest to work from dark to light. This means your base plate will be rough (remember rough = dark?) and you will be adding pva to lighten it (ie smooth it out, smooth = light)
Start with a piece of rough cardboard, in this example I used mountboard and peeled of the top layer of paper to reveal the rough inner core.
Mark out your plate
For the test piece divide the plate into about 8 stripes, number these 1 – 8.
This is your guide for painting successive thin coats of pva on to the plate.
PVA glue – a great all purpose glue
I buy cheap builders pva from the diy store, this comes in 5ltr bottles and is much cheaper than going to an art shop.
The consistency can vary, some pva comes out of the bottle quite runny, while some needs to be scooped out of the tub.
Whatever you start with, we will be diluting it to the consistency of single cream.
Why dilute it?
If you have made a collagraph plate with texture on it and you coat it with thick pva glue you will only see the texture of the glue; your carefully constructed textures will be obliterated by the gloopy stuff.
Don’t dilute it too much though!
What we are looking for is a liquid rather like runny single cream. This will flow easily on to the plate and cover the textures with a thin layer of glue, allowing the texture to remain, but slightly smoothing the roughness and filling the deeper indentations.
BUT in order to keep the texture of your collagraph plate showing you must apply the glue in thin layers, each layer smooths it out a bit more, making it lighter, while still allowing the texture to show.
Test your mixure
If you dilute the glue too much it will take lots of coats, a lot of drying time and ages to lighten the plate; so a bit of trial and error is needed with the dilution. You may need to adjust the consistency of the pva depending on how rough your plate surface is, so a test plate is very useful before you start on the real thing.
Tip; Add a bit of colour to help keep track
When it is dry on the plate diluted pva is transparent and it is hard to see where you have put it. To help you keep track of where you have been, add a bit of coloured ink to the pva mix. This won’t alter the texture but will stain the glue and make it easier to see the painted layers.
Paint layers of pva for graded shading
Begin by covering the areas 1 – 8 with a coat of thinned pva to which you have added a bit of ink.
Let it dry, then paint areas 2 – 8, when that’s dry paint areas 3 – 8 and continue like this till you put the last coat on area 8 only.
The successive layers of pva will gradually lighten the texture of the plate from the dark (rough) beginning until the last area which should be quite smooth and shiny by the time you have finished.
(The added ink has made the colour of the pva darken towards the smooth end of the sample.)
Sealing pva is important
Seal the pva with a thin shellac based varnish (sold as straw-hat varnish, button polish, French polish) See the blog post on shellac for more info.
You can also use thinned acrylic gloss medium, or thinned acrylic floor polish to seal pva. Do a few tests on sample plates to check what gives you the best results. I must stress that the sealer needs to be thin, otherwise it will clog up your textures, and only one coat is needed, all you are trying to do is seal the pva, not weatherproof a yacht!
If you don’t seal it, when you run it through the press the damp printing paper will stick to the plate, seriously messing everything up.
Print the test strip
Once the sealer is dry ink the plate up as intaglio and print it. You should find you have a graded strip of colour which fades from light to dark.
If it doesn’t grade smoothly you will need to adjust the dilution of the pva or the number of coats of pva. The process can be a bit tricky so don’t be discouraged, there is always an element of trial and error involved before you get it working right.
Tip; lightening a whole plate, or sections of it
In this graded shading technique we use the pva with a definite purpose, but if you have made a plate with too much texture or very rough materials a coat or two of diluted pva all over it will help to lighten it and make it easier to print.
(Dont forget to seal the pva with shellac or something similar.)
Making different shapes with highlights
In this example I am using carborundum wet and dry paper stuck to a piece of card as the base plate. Because this is a very rough surface it will hold a lot of ink and print dark. If your surface is dark to start with, a white pen is useful for sketching the graded areas.
Draw a template on the plate
Use a soft pencil or felt pen (leaving no indentations) outline the area you want to be lightest.
Add about 8 more contour lines around this until you arrive at the darkest area.
Number each band, 1 being the darkest, 9 being the lightest.
Paint the layers to make graded shadows
As with the test plate cover the largest shape with one coat of pva, and continue adding layers till you reach the smallest shape.
Seal the pva with shellac and print it.
After I printed this plate I thought it needed extra pva to make the shapes more distinct. Adding more pva once the plate is printed is tricky as the surface is greasy; clean as much ink off as possible and hope for the best! The second print has more pva on the plate.
Working on a plate with texture
I made a textured plate using torn and cut papers, and then added a big pva circle, with progressively lighter circles within it. The textures show through but there is a sense of structural form to the image that is solely down to the layers of pva.
In this detail you can see the guide pencil lines for successive layers of pva to make a graded shadow.
This plate is made from tile cement with different textures worked into the surface. The pva layers provide a light centre emerging from the darker texture of the tile cement.
the images show the collagraph plate with layers of pva, and the resulting print with a graded light in the middle.
Making collagraph plates with graded shadows can be tricky, and you must be prepared to make a few test prints before you get it working for you. However the idea of applying layers of pva to lighten areas of the plate can be used in many ways, and is a very useful technique to give new dimensions and depth to your prints.