The Dyer's Guide / Being a compendium of the art of dyeing linen, cotton, silk, wool, muslin, dresses, furniture, &c. &c.; with the method of scouring wool, bleaching cotton, &c., and directions for ungumming silk, and for whitening and sulphuring silk and wool; and also an introductory epitome of the leading facts in chemistry, as connected with the art of dyeing

by Thomas Packer

NUT-GREY.

The fustic decoction, archil, and a little logwood are put into water moderately hot, the silk is then returned, and when the liquor is exhausted, the silk is taken out, and to soften the colour the solution of sulphate of iron, or the black vat, is used. The silk is then returned once more, and if the colour does not appear sufficiently even, some red spots still remaining, it may be concluded that it requires a little more sulphate of iron.

Observe that, as sulphate of iron is the general base of all greys, if this be deficient in quantity, the colour is apt to change in dyeing, and to become rough and uneven.

To know whether the colour be sufficiently softened, it should be examined, and if it wet easily, after having been wrung on the peg, it wants sulphate of iron. On the contrary, if it wets with a little difficulty, the colour is sufficiently softened.

Too much sulphate of iron stiffens the silk considerably, making it harsh, and even depriving it of a part of its lustre; to remedy this it must be extra washed and wrung at the peg; this process carries off the sulphate of iron.