The solution when ready is to be kept in a closed bottle.
Generally to the colors which are used for hair-veined edges and marble more gall is added than to those used for drawn edges. It is, therefore, easily understood that with these, a more intensively acting expanding medium must be used to spread out the strong colors into veins.
The sprinkling water is here of great service, because, although ox-gall in its pure state possesses a sufficient expanding power it is here more desirable to produce beauty of forms. In this respect the gall is much inferior to sprinkling water, the former producing all kinds of forms, the latter only beautifully round and oval ones.
For marbling, the ground color is prepared with gall so far, until it slightly pushes the other colors aside and then, by and by, so much sprinkling water is added until the desired expanding power is reached.
Every ground color which is prepared with sprinkling water spoils on standing two or three days becoming slimy and viscous, and, for economy's sake, not more color should be prepared with sprinkling water than is required for one marbling process.
For hair-veined edges, the sprinkling water is used in the same way as gall. Use a large painter's brush or whisk and move the colors by beating into veins, with this brush or whisk through a slot, or throw the sprinkling-water upon the color by means of the sprinkling brush and sieve. In both cases the same result will be achieved.