This section is from the book "American Library Edition Of Workshop Receipts", by Ernest Spon. Also available from Amazon: American Library Edition Of Workshop Receipts.
Filter the emulsion through a piece of moist flannel in the glass funnel, placed in the tin funnel as described hereafter; filter into a small pitcher that will hold about 6 oz. You can have several of those small pitchers in hot water; as you empty one, you can be filtering more while you use the others. The small pitchers are for flowing out. Have your plates cleaned as described hereafter, and have them about as warm as when you Tarnish. Hold the plate with the left hand, the long way towards you, pour some emulsion on the centre of plate, let run to the farther right-hand corner, then to farther left-hand corner, then to corner you have hold of, and off at the nearest right-hand corner; leave sufficient on the plate to make a -rather opaque film. Practice will guide you how thick to have them. If they come out too intense, you have too much on: if too thin, you have not enough on. Move the emulsion on the plate until it is smooth, and then place upon screw-eyes as described hereafter. When you have 6 flowed, the first one will be ready to put upon a rack to dry. As soon as a plate is coated, it must be put in a dark place to dry - not even a red light should get to the plates after they are flowed.
The place you put them to set should be shaded from all red or white light; a dry plate on a negative exposed for 5 minutes to a red light will make a transparency; so, of course, will fog if exposed too long to red light in making and drying. The plates will dry in a few hours and are ready for use.
The alcohol and albumen are added to hasten the setting and drying, and to aid in the flowing. Gelatine and albumen flow more readily than gelatine alone; the albumen also helps to keep the silver in suspension in the gelatine.
 
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