Marek Liska Examining Colour in Slips and Glazes

Colour in Glazes: Technical

TECHNICAL PROJECT: Rationale Penguin Books had immence cultural impact in UK and other English speaking countries. It brought inexpensive fiction and non-­‐fiction to the mass market, educating, and influencing public debate in Britain, through its books on British culture, politics, the arts, and science.

Orange is the most prevalent colour in Penguin Books designs, I am therefore using it as colour that symbolises possibility for social and personal growth.

I found number of good colour pallets around orange, but one with split complementary colours: blue and purple stood out visually, and belonging in the Penguin colour scheme with dark blue representing Biography and Purple representing Essays.

I started with a search for multiple recipes of the chosen colours in Earthen Ware and Stone Ware, which would give me glaze bases and colours which I could then combine and refine.

I tested 4 SW recipes with one very successful Barium based glaze producing interesting dark blues with orangey halo on White Saint Tomas, and another glossy Soto Amber with interesting double colouration, but in green and browns.

Adapting the 2 base glazes, I stained them with commercial stains, which however burned out or in case of Lilac and Rosso Red Stains just reduced in vibrancy.

Therefore, I started experimenting with combinations of oxides to mixed into my leftover stained batches, referencing oxide combination sheet in our glaze room.

In the Barium based glaze I used: Vanadium + Cobalt Carbonate + Titanium Dioxide produced matter, more even, lighter blue. Manganese Carbonate produced very dark uneven purple.

Vanadium + Rutile didn’t show up and the glaze remained white.

In Soto Amber I used: YIO + Rutile + Vanadium producing just light brown with streaks of blue.

Cobalt Carbonate + Manganese Carbonate + Rutile producing dark background with interesting blue streaks.

And RIO, browning the Rosso Red stain.

I had more luck in the Earthen Ware glazes due to the simplicity of using commercial stains.

Finding another 4 different glazes, mainly Lead based, but one with Wollastonite and Strontium carbonate as fluxes which proved as most stable on different clays, pleasant surface and gloss, not settling down and good colour response.

I was able to use colorant combinations from the other glazes to adapt the non-­‐toxic base glaze, and experiment with other combinations, to produce a range of oranges, yellows and dark blue purples.

If I had more time I would really go for a bit more scientific/controlled way of testing the additions to perfect the colours, rather than my very quick, mostly intuitive decision making.

The fact that I opted for spraying my final work, made the glaze much brighter, but at least I’m not having brush streaks or loosing any details in texture.

The latest test piece glazed with my Penguin Purple, Penguin Yellow, Penguin White and Penguin Orange applied by spraying were acceptable. The one directional application even suggested sun exposure, as if sun rays sprayed the piece, giving direction to the growth.