Coloring slip with oxides

Color
  • CoO
  • CuO
  • Fe2O3
  • Cr2O3
  • MnO2

Slip clay can be colored using metals in the form of oxides. These produce deep earthy colours, the shades will vary depending on the percentage ratio of oxide to clay weight. Glazing will also affect the color of the clay, in general a clear gloss coating will make the color much darker.

Adding oxides can flux the clay, lowering the firing temperature, it is best to not add more than 5% of the slip weight.

Oxides are toxic if inhaled or ingested, can irritate skin, eyes and cause respiratory distress. Wear protection when handling.

0.25% - 5%

Always weigh the clay as the density of the slurry can vary. Weigh the oxide powder according to the quantity of the clay.

Min. 10 minutes

Mix the powder into the liquid clay using a propeller mixer (an electric mixer or immersion blender works as well) for a minimum of ten minutes to ensure even pigment distribution.

2x

Sieve the mixture two times during the mixing process to break apart any oxide powder clumps and remove any impurities from the clay using a 80-100 mesh sieve.

Iron oxide Fe2O3 0.25% - 5%

Red Iron oxide, black iron oxide, brown iron oxide and yellow iron oxide produce shades of red in fired clay, from a pale salmon to a deep burgundy. These samples are made using black iron oxide, which In liquid state, the clay is a blueish grey.

Chromium oxide

Cr2O3 0.25% - 5%

Chromium is a very vivid oxide producing greens ranging from soft chartreuse to deep forest green.

Cobalt oxide

CoO 0.25% - 5%

Red Iron oxide, black iron oxide, brown iron oxide and yellow iron oxide produce shades of red in fired clay, from a pale salmon to a deep burgundy. These samples are made using black iron oxide, which In liquid state, the clay is a blueish grey.

Manganese oxide

MnO2 0.25% - 5%

Red Iron oxide, black iron oxide, brown iron oxide and yellow iron oxide produce shades of red in fired clay, from a pale salmon to a deep burgundy. These samples are made using black iron oxide, which In liquid state, the clay is a blueish grey.

Copper oxide

CuO 0.25% - 5%

Red Iron oxide, black iron oxide, brown iron oxide and yellow iron oxide produce shades of red in fired clay, from a pale salmon to a deep burgundy. These samples are made using black iron oxide, which In liquid state, the clay is a blueish grey.