Take 1 gallon of water; in which dissolve
3 libs. of nitrate of lead,
1 lib. of binacetate of copper; to the solution, add
1/2 lib. of subacetate of lead; and thicken the mixed solution
with
3 libs. of gum.
6 libs. of pipe clay. Grind all the ingredients together, and
pass through a searce.
After treating the goods as in No. 1., they must be winced for half an
hour in a solution containing 5 ounces of bichromate of potash, per
piece of calico, and also in a dilute muriatic bath, till the chrome
yellow become sufficiently bright.
A chrome orange reserve may be made by introducing a larger proportion
of subacetate of lead, and passing the reserve printed goods through
weak milk of lime, as already prescribed for producing an orange by
chrome.
The basis of the resist pastes used at Manchester is sometimes of more
complex composition than the above; since, according to the private
information I received from an extensive calico printer, they contain
“china clay” (instead of pipe-clay which often contains iron) strong
solution of sulphate of copper, oil, tallow, and soap; the whole
incorporated by trituration with heat.
In the Lancashire print-works, a little tartaric acid is added to the
nitrate of lead, which prevents the colour from taking a dingy cast.