Illustration: s--black; b--blue; r--red; yellow in centre.
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.
The colours must then be traced crosswise with the stick in this form and then likewise with the comb. Neither stick nor comb should be dipped more than about 2 mm. below the surface, otherwise the body is set in motion and the colours disarranged.
The combs should not be made too fine, 30 to 35 teeth for every 10 cm. is the best width and sufficient for most cases. If the comb is drawn back again from the other end it produces drawn-back marbling; this is rarely applied.
The finished comb marbling can be still further varied if figures are traced in it with the stick as shown in Fig. 46.
If a double comb is made--one that allows two combs to pass each other, their teeth being 2 cm. apart--bouquet or peacock and eye marbling can be produced. The double comb is drawn over the length of the trough, at the same time moving the two combs up and down evenly. This motion causes the colours to assume the form shown in the accompanying illustration.
Bouquet or peacock marbling is produced by drawing the double comb through the finished comb marble design, and if the double comb is used immediately after the cross tracing with the stick, eye marbling is the result.