I have been on a quest for quite a few years to find a material that will take detailed impressions of 3d textures, and that you can also print directly from. I wanted something flexible that would mould round shapes and capture details of the texture. This wonder material would then set enough to be flattened out, inked up and printed in a press.

There are lots of options for moulding materials that will take impressions but not many that can also become a printing plate. Some of the things I have tried include air drying clay, car body filler, polymorph, mouldable foam, and silicone. These all take impressions but none made very good printing plates.

The answer came, as many answers do,  when I was messing about with something else……

Latex

I had a bottle of latex for another mould making project and thought ‘I’ll just give that a go and see if it prints’.

Yes! This is the best thing I have found so far for taking impressions of textures from 3d objects and then printing them directly. Latex picks up precise fine details, moulds round contoured shapes and stretches out flat. The thin rubber plate takes intaglio and relief ink and you can print it with or without a press.

ammonite casts and print

What is latex?

Latex a natural substance produced by plants, according to Wikipedia the name given to latex by indigenous Equator tribes who cultivated the rubber tree, was “caoutchouc”, from the words caa (‘tear’) and ochu (‘tree’). So we will be making printing plates from the tears of trees, which is rather a romantic, if sad, idea.

Latex is a water based liquid which dries on contact with air. Warmth speeds up the drying, cold and damp delay it. Exposure to UV light can degrade latex, and if you are storing it don’t let it get too cold or it will go lumpy.

There are lots of places selling latex on line, you want latex for mould making, not vulcanised latex. When making moulds a thickener is added to the latex, but for printing plates you don’t necessarily need that.

It is pretty smelly – remember Copydex? – have good ventilation where you are working, or do it outside if possible.

bottles of latex
tray of things to be cast in latex for printing

What type of things can you cast?

The surface needs to be continuous, any breaks in it will allow the latex to flow underneath. (I once tried a birds wing, this was not successful as the latex crept under each feather.)

Latex picks up tiny details, but for printing the surface texture shouldn’t have extreme variations in height.

The flexible latex cast will need to lie flat  to print it, so gentle curves or contours work best. If the curve is too great it will have folds in it, alternatively you can cut it so it is flat.

Look for objects with interesting textures, and shapes that you couldn’t put through a press. Things that are too brittle, too thick, not flat enough, too squashy or too big for the press can all be cast and printed from latex.

I love using it for natural things from the beach or woodland. Some things I have cast and printed include; sea shells, bark, fish, fruit with interesting skin texture, very big leaves, sea urchins, rocks with texture on, barnacles, coral, ammonites….. once you get started you will find things to cast everywhere.

Tray of sand with clingfilm on top

How to cast latex printing plates

Get your objects ready for casting;
I use a tray with sand in it, covered with a piece of cling film.
Bed your object into this, so it is supported and the liquid latex won’t run round and underneath it. In the picture of the fish below notice that I’ve used a knitting needle to hold its fin in position.

If you are doing something flat, eg a leaf or a feather, spray it with glue and stick down flat on a sheet of acetate to stop the latex running underneath it. A good glue to use is 3M 75 Repositional Spray which remains tacky so things can be held down and also removed quite easily.

If your object is too big for a sand tray you can fix tape or plasticine round the area you want to cast to prevent the latex running off. The tape round the melon below is helping with this.

a fish ready to cast in latex
casting a melon in latex

Coat your items with latex
When all your things are prepared, tip some latex into a plastic pot.

Using a synthetic brush paint a coat of latex onto your object. (It is hard to clean latex out of natural bristle brushes). Clean the brush with water straight away. Cover your pot to prevent the latex skinning over.

Let it dry, and repeat this till you have three or four layers of latex.
For small things it is quicker to dip them into the pot of latex. The sea urchin below was done like this.

If you were making a latex mould you would add a layer of thickened latex at this stage to make it stronger. However we are making printing plates not moulds, and if you add thickened latex to your printing plate the brush strokes on the back will probaly show through the thin plate when you come to print it. This can look good, but it can also detract from the fine details. Runny latex leaves a smooth finish as it does not show brush marks.

casting items with latex in the sand tray
a latex cast of a seashell

Reveal your latex printing plates
When it is dry it goes translucent. Dust the back of the latex with talc to make it easier to handle, and peel it off your object.

Trim the edges with scissors if there are lumpy bits, and cut off any flaps where the latex has seeped under the object.

You will now have flexible latex printing plates with a unique textures. These rubber plates are surprisingly strong.

latex cast of a fish with edges trimmed off

Ink up your latex plate

Dilute your ink with linseed oil so it is quite runny. Paint it into the latex texture, and wipe it off with a rag, you can also blot it with newspaper to remove any pools of ink.

Then roll another colour ink on as relief. If you use white ink to roll over you can get almost photographic effects: see the ammonite at the top of this post for an example of this.

rolling ink over latex plates

Print your latex plate

Lay printing paper over your plate and run it through the press. The paper can be damp or dry, I think the prints are a bit better with damp paper but it can sometimes stick to the plate if your inks are too stiff. To see information about preparing printing paper see this post.

Have a supply of wet strength tissue, or other thin papers handy to create prints for chine collee.

Combine your latex plates with other printing plates, and add latex printed elements to your prints.

As your latex printing plates will all be odd sizes it is very helpful ot have a registration sheet to help you arrange them on the paper.

 

oyster shell from latex printing plate
casting and printing a sea urchin

Casting materials is an interesting approach to making printing plates, with scope for playing around with positive and negative textures. Collecting direct impressions from large or permanent fixtures the environment and bringing them into the print studio, opens up lots of potential possibilities for innovative printmaking.

So that is where my search for a moulding material that you can print from has led me. I’d love to hear from anyone who has suggestions or practical experience of any other materials which can do this.

latex cast of barnacles