Testing 1 2 3

Joseph Travis 2 weeks ago

The start of every project there is a lot of testing as I enjoy that part and a new project is often a great excuse to try something new, new glazes, new clay etc. In the last post I already showed the new clays I am starting with, plus add on to those Blackpool School of Arts buff clay and crank clay, as well as my own standard clay plus my standard clay with approx 5% red iron oxide added and some addition grog.

clay testing

The first job was rolling out small slabs and measuring 10cm lines on each so that when the clay is high fired we will know the shrinkage rate for each clay, this will help determine what size I'll screen print images so they will still be big enough once everything is fired.

Dicided clays on a workbench

I also threw rings of clay with a small foot on so we can test glaze samples on each clay body, each rind was divided into approximately 12 segments. They were still a bit wet when I divided them so I left plenty of finger marks.

In the 3D rooms at Blackpool, there are also materials that haven't been used in a while so my second job was reconstituting a selection of coloured slips and casting slips. There are a few moulds left around so I did some casting

various clay samples

That was half a days testing, the second half day was numbering all the clay samples so I can just make accurate tests knowing what sample is what.

slip samples

The slips I reconstituted on the previous visit were ready to be used so I rolled a buff clay slab and applied those, there is a possibility of using these through the screens, and is one possible test I need to do.

mixing oxides with screen printing medium

I mixed some black iron oxide with screen printing medium to try out printing on clay as an initial test.

screen printed concentric circles on clay

Working with the technician I screen printed the mix of black iron oxide and screen printing medium onto a slab of clay. It looks good at this stage. We will have to see once it is fired and glazed is this is sufficient.

There are some unphotographed samples where I mixed various ratios of screen printing medium to oxides and stains, I'm not sure how they will "stick" through the firing processes or whether the slip will work better, but that will take some work getting it to the right consistency.

The next stage is firing all this and testing various images on the risograph to try and work out what it is I want to produce image-wise.