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

On dyeing silk and cotton BLACK with a blue ground.

It is remarkable, that although an indigo ground for wool enriches the black, yet for silk and cotton it is not generally considered necessary. Latterly, however, we believe the dyers of black on cotton do first give it an indigo ground before the black is given. This is, nevertheless, not a new method, for D'Apligny describes the process in his Art of Dyeing, for linen and cotton yarns; these are first dyed sky-blue in the vat, then wrung out and set to dry. They are galled in the proportion of one part galls to four of yarn, being left twenty-four hours in the gall liquor, wrung out anew, and set to dry: about ten pints of iron liquor to every pound of yarn are then poured into a tub, in this the yarn is turned on sticks, and worked with the hand for a quarter of an hour, it is then wrung out and aired. This operation is twice repeated, adding each time a new dose of the iron liquor; the yarn is aired once more, then wrung out, well washed, and dried. To complete the dyeing of the yarn a weight of alder-bark equal to that of the yarn is boiled with a sufficient quantity of water for an hour; to this is added one half of the bath which has served for the galling and sumach. The whole is boiled for two hours. When cold the yarn is put in and worked, aired occasionally, and then left in the bath for twenty-four hours, when it is wrung out and dried. To complete it, it is steeped and worked in the residue of a bath of weld, to which a little logwood is added; it is then taken out, wrung, and immediately passed through a tub of warm water, into which one part of olive oil to sixteen of yarn has been poured. It is finally wrung out and dried. See Ure's Berthollet, vol. ii. page 18.