CHAPTER XI

PRINTS ON FABRICS AND IMITATION ENAMELS

Making prints on silks and fabrics is essentially a specialty

adapted for home work. It is not always easy to get good prints,

but the following method by A. J. Jarman can be relied upon if the

manipulation advised is followed carefully. A first essential is

absolute cleanliness, and a second, the use of distilled water in

mixing solutions. Make a salting and sizing solution as follows: Soak

125 grains of hard gelatine in 25 ounces of water. Add common salt 100

grains; ammonium chloride, 25 grains; magnesium lactate, 125 grains.

Warm the solution so that the gelatine completely dissolves; soak the

fabric in it and suspend to dry. Mix sensitizing solutions as follows:

No. 1: nitrate of silver, 120 grains; water, 4 ounces. No. 2: citric

acid, 50 grains; white sugar, 50 grains; distilled water, 20 ounces.

Soak the fabric in No. 1 for three minutes; drain until surface is dry

and draw it carefully through No. 2. Hang up to dry, when it is ready

for printing. This sensitizing should be done in the dark-room or in

yellow light. The fabric should be kept under pressure, when it will

keep good for about a week, but it is better if used fresh. The print

is made in an ordinary frame. If the fabric is to be examined during

printing, it should be attached by light touches of glue to a card.

It is a good plan to sensitize a small extra strip of material which

may be used as a test on the negative to be printed from. Having made

the test, the picture can be printed by time. Prints should be masked

with a clean edge or vignette, and a margin of fabric left all around

in case the picture is to be sewn into a cushion. Wash the print in

several changes of water and tone in saturated solution of borax, 3

ounces; water, 30 ounces; chloride of gold, 2 grains. As soon as toning

is complete, wash in two changes of water and fix in a 10 per cent

hypo bath. Fixing takes about ten minutes. After well washing in clean

cold water suspend by clips to dry. If the fabric is very thin the

preliminary salting solution may be 50 per cent stronger; otherwise the

formula as given will answer every purpose for silks and other fabrics.

To those familiar with carbon printing the making of imitation

enamels, _i.e._, photographs on china, plates, pottery, etc., offers

an attractive home hobby. A carbon print from a good negative is

transferred onto a porcelain or other vitreous support, and then,

instead of being submitted to the great heat necessary for fusion,

it is japanned—that is, the surface of the image is covered with a

transparent varnish. The first stages of the work present no unusual

difficulties, for they are merely carbon work. A tissue containing a

maximum of pigment with a minimum of gelatine should be chosen. This

is to a certain extent porous, and by allowing the first coating of

varnish to penetrate tends to bind all more closely to the support.

Any color of tissue may be used and the picture may be tinted or

colored if desired, before being japanned.

A good brand of amber or copal varnish should be used, of the kind

known as “stoving varnish,” or it may not stand the heat of japanning.

Amber varnish is slightly the harder, but copal is preferable as being

colorless. A very thin layer of this varnish is spread on the mounted

tissue with a camel’s-hair brush. This first coat should be mixed

with an equal quantity of turpentine—it will then spread thinner.

Brush marks will disappear during the stoving. One coat must be

thoroughly dry and hard before a second is applied; if not, the unequal

contraction may in the final stages cause innumerable little cracks.

Let the plaque dry in a warm dust-proof place. When a sufficient

thickness of glaze has been obtained by repeated coatings and dryings,

the enamel is ready for stoving. This may be done in a gas-oven or the

kitchen stove. A gentle heat, not less than 150° F. or more than 200°

F., should be kept up for five or six hours. The enamel is then allowed

to cool. When cold its surface must be polished, first with pumice

powder and finished off with putty powder.

Photography at home · 第 11 / 11 章