578

DYEING AND CALICO PRINTING.

details of this operation are described in p. 309. The exa<ff procedure fol-lowed in this case is as follows :—After washing out of the dye-beck, the piecesare next hot-watered, and then soaped at 140° F. for forty minutes. They arenext washed and soaped again, in fresh baths, for the same period of time, butthe temperature is increased to 160 0 F. They are again washed in plainwater, in order to remove traces of soap, which would interfere with the nextprocess. They are then cleared with a very dilute solution of chloride oflime, washed again in clear water, and finished. The ground is now white,and the colours of the design have lost in depth—for which an allowance wasmade in the original intensity of the shade—and gained in brightness.

The first pattern on page 579 illustrates a different style of madder-work com-bined with aniline black. To produce this effedt the pieces are printed first withso-called “acid,”— i.e., lime-j.uice,—at 8° Tw,, thickened with gum-substitute(see Style I., No. 48, p. 572,.and p. 318), to produce the white figure. Wherethis mixture is applied, the mordants, which follow next, are prevented from

i

j

Madder Style. (After Clearing)

attaching themselves to the fibre; and when the pieces ultimately come outof the dye-beck, this figure is found, not dyed, but merely stained with a faintred, which is entirely removed in the clearing process, leaving a white, asshown in the pattern. The black design is next produced with aniline (seeAniline Black, p.211), and remains unaffedted during the subsequent opera-tions. The pieces are then “ covered ” with iron liquor (see Nos. 30, 31, &c.)to produce the small design in dark purple, and padded all over in a weakeriron liquor (see No. 33) to give the light purple ground. The goods are thenaged for thirty-six hours, or longer, at 8o c F., dunged, washed, dyed in themadder-beck,—which produces the two shades of purple according to thestrength of the mordants,—and cleared.

In some printing establishments on the Continent, hydrofluosilicic acid isemployed instead of citric acid.