On the other hand, this method of stencilling has certain disadvantages. It is rather complicated, needing the use of a fixing bath of tartar emetic, a very active poison, by the way, although more uncomfortable than actually dangerous when taken by mistake in one dose, because of the severe vomiting it produces almost immediately. And then, too, the results at best are not really fast to light, and in the case of light pinks and yellows are distinctly fugitive. _Vat Color Stencil Pastes._—Many experiments have been made in our laboratory to work out a satisfactory stencil paste, so that Indigo and other Vat dyes could be applied, simply and easily, with no more difficulty than the usual one of brushing the paste in carefully, and then steaming as soon as possible. In these stencil pastes the Indigo and the other Vat dyes are reduced with the aid of caustic alkali and hydrosulphite before being mixed with the paste, and some special precautions are taken to prevent, as far as possible, the oxidation of the dyestuff before it gets well into the fibre. But, as the ordinary hydrosulphite is apt to decompose on standing, especially when it is wet, it is always best, just before using, to mix well with the paste a little fresh reducing agent, dissolved in a drop of hot water. The reducing agent that should be used for this purpose is not the ordinary hydrosulphite of soda, used for vat dyeing, but a compound of sodium hydrosulphite, “Stencil Salt,” which has the property of keeping better than the other, and also of not acting as a reducing agent until it is heated. This, then, is stirred into the Vat color stencil paste, just before using, and then, when the goods are steamed, the heat and moisture combined will enable it to reduce the color, which will be carried into the fibres in a reduced and dissolved condition. After steaming well for five minutes the color should be developed by a bath in hot soapsuds, after which the goods should be rinsed and dried. With care this process will give very satisfactory results, perfectly fast to both light and washing, after the first loose color has been washed off.