s—black; b—blue; r—red; yellow in centre.
A drop of colour is let fall from the black brush upon the body, the surface of which had previously been drawn off with a strip of paper; the surface of this drop must be about the size of a crown piece. If part of the colour sinks to the bottom, the body is too thin or the colour too thick, or the drop was too large and could not spread quickly enough; in the latter case the surplus colour will be seen lying at the bottom and will have no connection whatever with the colour on the surface; but if a cloudy connection can be traced from the surface to the bottom then the body has already become sour and in most cases unfit for use. If the colour does not retain its smooth outlines and becomes jagged, it also shows that the body is too old. If, however, the drop extends as desired and shows none of the faults above mentioned, a drop of blue colour is let fall in the centre of the first, which drives out the first drop in the form of a ring; when it has not this effect, but strongly contracts again, a drop of gall must be added, the colours wiped off to the sloping partition, and the whole process repeated. If the action of the colour was too strong, a little undiluted colour must be added. If the result is satisfactory, a drop of red is added to the blue. The colour scheme is seen in the accompanying drawing. Lastly, yellow is dropped into red, and black is thereby reduced to a very thin ring.
Before each new sprinkling, the old layer of colour must be wiped off. To do this, cut strips of stout waste paper about two fingers in width and a little longer than the trough is wide. The edge of the strip is placed slantingly at the end of the tank in the surface of the body and the surface colour drawn off, at the same time lightly pressing the ends of the strip against the sides of the trough.
When the colours are satisfactory, the little stick is traced in and out amongst them. If too much colour follows the stick, the body is too thick; only a narrow line of colour must follow the stick.
If the colours are thus correctly prepared, the whole trough is sprinkled in the following manner: Along the middle of the trough the darkest colour is sprinkled in what we might call links, that is, each drop is linked to the one preceding.
Fig. 44—Suggestion for sprinkling colour.
The second colour is sprinkled on in the same way; one circle, however, is on the right and the other on the left of the centre colour. Into each drop of the second colour let a drop of the third and then of the fourth colour fall.
