Creating Coloured Porcelain

I have been experimenting with adding colour into porcelain slip. I've decided to colour the clay body, rather than adding a glaze or coloured slip on the surface, as I have been creating 3D textured pieces which I feel would lose their definition if I covered them. To get bright colours, quite a lot of underglaze needed to be added to the porcelain, because the porcelain is white, so all of the resulting colours would be tints.

I decided to test the colours at different temperatures as well as different concentrations of colour. Starting at 1g of underglaze to 100ml of porcelain slip, I also tested 2g, 3g and 5g. I poured out the slip onto plaster bats to dry, then cut each into 6 sections to fire at 1000, 1060, 1140, 1200, 1230, and 1260 degrees Celcius. I felt like this would give me a good overview of how the firing temperature and concentration alter the colour.

I used Picasso blue, black, turquoise, and lime green underglaze powders, and I plan to start mixing my own colours now I have a better idea of how they behave at different temperatures and concentrations. I remembered to label them before I fired them because I've made the mistake before of getting a beautiful result and forgetting how I got there!

I will make some texture tests with the coloured clay to see how the surface works with the colour, and I will also try putting underglaze powders into plastic clay rather than slip, to see if a uniform texture can be obtained by wedging it into the clay.

Ceramics: fired clay gloves.

 I really liked the colours the clay became when it was fired. I think glazing would make the colours more vibrant, but I didn't want to lose the texture on the surface.

Some of the small pieces got lost somewhere between being made and being fired, so some of the gloves are incomplete, but I don't mind this, because I have been looking at pottery shards, which are always a piece of something that was once complete.

For this glove, although it is only from one half of the mold, I had all of the pieces and was able to sew them all together, to reconstruct what it once was. My favourite part of this piece when I finished was not the look of it (although I do like the colours very much) but the sound it makes when you move it. It jangles when you pick it up, it sounds broken, fragile. I also think using the thread instead of wire or string adds to this sense of fragility and delicacy.

Ceramics: Using the plaster mold.

After making my two part plaster mold, I found that one side of it was not hard as I expected it to be, but spongy and crumbly when I touched it or tried to put clay in it. For that reason, I decided to put it in a drying oven, and just use the other half, to see if I could get any casts of my glove from that while the other half was drying.

I think this worked well, because the textile texture transferred very well to the clay, and was very realistic on the surface.

Next, I coloured some clay, and put some of that in before the rest of the clay, so it would come out on the surface. I liked the effect this had, but unfortunately, the clay had dried out a bit, and the thumb cracked off. At first I thought I would just crumple it up and try again, but I felt this was a waste of the spot pattern I had made, so inspired by my research into Tania Covo and Cleo Mussi, who both use shards of reclaimed pottery in their work, I decided to carry on, and used a needle to make holes in both pieces, to sew them back together later. Just because it wasn't perfect, didn't mean it couldn't still be used. After this, I decided to do some more research into casting, and found Janet Haige, who also used stitching in her casting, and used textiles and lace to make imprints in clay.

 In my next casting, I cracked it even more, so there would be more emphasis on the sewing.

When the other half of my cast came out of the drying oven, the plaster was a bit harder but still stuck to the clay quite a lot, and made it very difficult to get the clay glove out of the cast. My clay glove from the two part cast also cracked and stuck in the cast, so I made holes in this one as well to sew back together later.

One of my casts from the two part mold did come out whole, and I used the coloured clay to make patterns, but I found that this didn't look as exciting as the ones to be sewn together.

Close-up of the coloured clay and texture of the glove.