Starting with Slip technical, exploring colours in slips with Morgan alongside Field module.
I started with a search across library books and the internet for base, white slip recipes of which we mixed 7.
We applied them on terracotta and White Saint Thomas tiles in 3 various layers fired to EW and SW temperatures, half glazed. Also fired on its own.
The blobs of slip were created by piping about 20ml of the individual slips onto plaster bat and gently smearing them. However, they proved extremely fragile after drying, some of them quickly cracking in the process of drying. Anyway, the colour was the same as 3 coats on the tiles; on the other hand, we wanted the blobs of slips for more interesting and easier presentation of our outcomes, giving us possibility to use them to create an installation piece.
The experiment allowed us to see that the simple recipe used in our glaze room: 50/50 of Ball and China clay has the best result in producing white slip in EW temperature, meanwhile using Porcelain powder slip is whitest for SW temperature.
Morgan’s temperature test showed us the colour changes in number of oxides and staines in EW and SW temperature.
Using the chosen 50/50 slip he stained it with Red, Yellow, Purple and Synthetic Iron Oxides, as well as Coral stain and Chrome Oxide.
Half glazed, they reveal a dramatic change in colour.
This test made us stick with EW temperatures, with added bonus of reducing cost and environmental impacts, but being aware of increased fragility of EW products.
To further see the colour response of each slip recipe, we added 10% of Yellow stain to each recipe, bisque fired and half glazed at EW temperature, on terracotta tiles.
Most of them look the same, except 1 weird recipe that melts on SW.
These experiments gave us really just the starting point, establishing processes and testing techniques, as well as backing up choice for base slip and temperature.
Rigorous testing of combinations of stains and oxides.
We want to be able to produce a specific colour pallet in specific shades, similar to Jin Eui Kim’s carefully mixed tonal range of his engobes, to create an illusion of curves and voids.