| Albumen of one Egg. | ||
| Water | 7 | ounces. |
| Saturated Solution of Bichromate of Potash | 1 | ounce. |
Place the white of egg in a bottle containing a lot of small pieces of perfectly clean glass, then add the water and shake it well for a minute; then add the solution of bichromate and again shake it well. Now place a pledget of cotton-wool in the neck of a glass funnel, and pass a few ounces of clean water through (if this is not done, there will be difficulty in getting the albumen to filter); drain as much as possible of the water away, and then filter the albumen into a clean bottle; when all the solution has gone through, remove the cotton-wool from the funnel, which well wash, then recharge with a fresh pledget, pass some water through, and again filter the albumen solution through, this time into a ten ounce glass-measure, which is to be used for pouring from upon the zinc. The stem of the funnel should be long enough to reach the bottom of the glass measure, so that the formation of air-bubbles be avoided, which is impossible with albumen if the funnel is not below the surface of the filtrate.
Of this, pour over the zinc sufficient to well cover the surface, letting any surplus go into the sink; then set the whirler revolving, coat again, and {46} again whirl; now examine the surface, and if it is free from dust, spots, and air-bubbles, remove the zinc and dry it over the spirit stove. But if either air-bubbles or dust be present, wash them off under the tap, and begin again.
The film being dry, get the printing frame ready, see that the surface of the glass inside is quite clean and free from grit, as also the back of the negative, taking special care that the ridge of varnish which often forms at the bottom of the negative be removed, as the slightest inequality of surface will surely cause disaster directly the screws exert their pressure.
Do not lay the negative into the frame flat upon the glass, but slide it in from one side, so as to carry any dust away from the glass front of the printing frame.
The negative being in the frame, film side up, lay the coated zinc upon it, face down, judging the proper position and placing the zinc flat down upon the negative; now put a piece of brown paper over the back of the zinc, then place the back of the printing frame in place, fasten down the cross bars and apply the pressure screws, evenly and gently.
Do not screw one side tight before the other has been touched, but screw down so as to tighten all as evenly as possible.
Even pressure being applied, see that the front of the frame is clean, and then expose to direct sunlight for five minutes. Remove the frame to the dark-room, unfasten the cross bars and remove the zinc, taking great care to avoid scratching its film against the film of the negative.
After wiping the inking slab with clean linen place a piece of the transfer ink, about the size of a small bean, upon the upper corner, sprinkle this with a little turpentine, and mix them with the palette knife until they are of about the consistency of printing ink.
Now with the palette knife spread some of this mixture as far as possible over the inking slab, and then distribute it with the composition roller. Roll to and fro, across and diagonally, until there is a thin, even coating of ink all over the slab (not touching the corner where the ink was mixed with the turpentine) and upon the roller; if the mixture is too dry and refuses to spread, sprinkle on a little more turpentine, but do not use too much, else it will take a long time to evaporate.