234

CALICO-PRINTING.

2. With regard to reserves the following general observations may be made.' Afteiprinting-on the paste, the goods must be hungup in a chamber, rather humid than loo dry,and left there for a certain time, more or less, according to the nature of the reserve. Indipping them into the blue vat, if the reserve be too dry, it is apt to swell, scale off, andvitiate the pattern. This accident is liable to happen also when the vat is deficient inlime, especially with deep blues.

1. Simple while resist paste for a full body of blue.

Take 1 gallon of water, in which are to be dissolved,

1 pound of binacetate of copper (distilled verdigris), and 3 lbs. of sulphate ofcopper.

This solution is to be thickened with

2 lbs. of gum Senegal, 1 lb. of British gum, and 4 lbs. of pipe-clay; adding afterwards, 2 ounces of nitrate of copper—as a deliquescent substance.

2. White reserve for light bines.

Take 1 gallon of water, in which dissolve4 ounces of binacetate of copper,

1 lb. of sulphate of copper; and thicken this solution with

2 lbs. of gum Senegal, 1 lb. of British gum, and 4 lbs. of pipe clay.

3. White reserve for the cylinder machine.

Take 1 \ gallons of water; in which dissolve

2J lbs. of binacetate of copper,

10 lbs. of sulphate of copper; and add to the solution

6 lbs. of acetate of lead; then thicken with

10 lbs. of gum; adding afterwards 10 lbs. of sulphate of lead.

After printing-on this reserve, the goods are to be hung up for two days, then dippedtill the proper blue tint be obtained. Finally they must be winced through dilute sulphu-ric acid to clear up the white, by removing the cupreous tinge.

3. Colored reserves.

1. Chamois reserve.

Take 1 gallon of the chamois bath (No. 1, page 232, at bottom); to which add8 ounces of nitrate of copper,

24 ditto of muriate of zinc ; thicken with6 pounds of pipe-clay, and 3 pounds of gum Senegal .

After printing-on this paste, the goods must be hung up for five or six days in a some-what damp room. Then after having dipped them in the vat, they are to be steeped inwater for half an hour, and slightly washed. Next wince for half an hour, through waterat 100° F. containing 2 pounds of soda crystals per 30 gallons. Rinse and dry.

2. Chrome yellow reserve.

Take 1 gallon of water; in which dissolve

3 lbs. of nitrate of lead,

1 lb. of binacetate of copper; to the solution, add| lb. of subacetate of lead; and thicken the mixed solution with3 lbs. of gum.

6 lbs. of pipe-clay. Grind all the ingredients together, and pass through a scarce.

After treating the goods as in No. 1, they must be winced for half an hour in a solut‘ oncontaining 5 ounces of bichromate of potash, per piece of calico, and also in a dilutemuriatic bath, till the chrome yellow becomes sufficiently bright.

A chrome orange reserve may be made by introducing a larger proportion of subacetateof lead, and passing the reserve printed goods through weak milk of lime, as already P re "scribed for producing an orange by chrome.

The basis of the resist pastes used at Manchester is sometimes of more complex com-position than the above; since, according to the private information I received from anextensive calico printer, they contain china clay (instead of pipe-clay, which often con-tains iron), strong solution of sulphate of copper, oil, tallow, and soap; the whole incorp 0 'rated by trituration with heat. ,

In the Lancashire print-works, a little tartaric acid is added to the nitrate of I ea ’which prevents the color from taking a dingy cast.

4. Reserves with mordants , or the lazulite style.

1. Black upon a blue ground. ct

At Manchester the black pattern is printed-on with a mixture of iron liquor and ex rof logwood, and the resist paste by the cylinder machine; in France the black is S lby the following recipe:— ..^

Take 1 gallon of decoction of galls of spec. grav. 1-04, mixed and boiled into a paste wi14 ounces of flour; into the paste, when nearly cold, there are added, . a to 38 ounces of an acetated peroxyde of iron, made by adding 1 lb. acetate of read tlbs. of nitrate of iron, spec. grav. 1-56.i ounce of gallipoli oil.