done to some of the tests. As well, line blends of
two colour additions were also carried out.

Colour Testing: Quick Method of Testing
Colorants (courtesy of Robin Hopper)

1) Mix in bow] 100 gm. of base glaze with water to

a normal brushable consistency.

2) Weigh 10 gm. of colorant (oxide, carbonate or

stain) and place it on a clean glossy surface (tile

or paper). Using a knife divide up the pile of colorant
(done visually) into half, then quarters. Divide one
quarter in two, then one portion in two. The pile
should look like this:

re
mG:

3) Make the test tiles of bisque with commonly used
Slips and observe range of colour effects. (Do not
forget to serial number the tile).

4) First brush one tile with base glaze.

5) Then add pile (A) of the colorant, mix well and
apply to tile @2.

6) Add pile (B) of the colorant to the mix, mix well
and apply to tile 3.

7) Follow same procedure for remaining colour until
seven tiles are done. The results will be approxi-

mately as follows:

- Base Glaze only

- Base glaze plus 0.625% colour.
- Base glaze plus 1.25% colour.
Base glaze plus 2.5% colour.

- Base glaze plus 5.0% colour.

- Base glaze plus 7.5% colour.

- Base glaze plus 10% colour
- Fire to required cone and record results.

Ss oF on Se tay a me
|

For added variation colorants can be cross blended.

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