Friday, 5 April 2013

Colouring cold porcelain: the fresco method

Cold porcelain has one particular quality that guarantees it will appeal to me: it's cheap.  I won't lie, this is primarily why I use the stuff.  But it also behaves in some quite interesting ways when you colour it.  People often colour cold porcelain by kneading ink or paint into it, and this works very well.  However, I prefer to colour my cold porcelain using the fresco method.  This method takes advantage of the fact that, unlike other polymer clays, cold porcelain is water-soluble.  When you make a fresco, you apply paint directly onto wet plaster.  The pigment gets absorbed into the plaster surface and colours the plaster itself.  And you can do exactly the same thing with cold porcelain.

I made these therapod claws to demonstrate what the fresco method looks like when finished.  You can see how it's possible to get a rich colour with plenty of depth and variation.  The translucent clay base helps to give this effect, but you can also use the fresco method on coloured clay to get different effects.



You start by making whatever object you want to make out of the clay.  You then take a soft paintbrush and use it to apply watered down ink or acrylic paint to the clay surface while it's still wet.  This dissolves the clay surface and allows the pigment to bind with the clay.

I like to start with lighter tomes and build them up gradually.

Here you can see a mixture of burnt sienna and burnt umber paint.   I finished off with some charcoal colour.

Getting a smooth colour without brush strokes takes a bit of practice - fresco isn't the easiest painting method out there - but I think the results are worthwhile.