Emulsion 1A Developing-Out Contact Printing Paper

PART ONE:

Preheat waterbath on a stirring hot plate¹ to 60°C. (Water level at 2 inches.) Illustration

Unless otherwise specified, solutions are assumed to be at room temperature. Chemicals and equipment not otherwise sourced can be purchased from Photographers’ Formulary² or your neighborhood household goods/hardware store.

Gelatin A:
13 g Photographers’ Formulary gelatin (250 Bloom) in
65 ml refrigerator temp distilled water. Bloom at room temperature 1 hour in 400 ml beaker.

Gelatin B: Same as A.

Salts:
4 g Masu seawater salt³ dissolved in
20 ml distilled water.
0.5 g KCl (Potassium chloride).
2 g citric acid.
0.7 g NH4Br (Ammonium bromide).
5 ml Everclear alcohol⁴.

Silver:
5.6 g AgNO3 dissolved in
25 ml distilled water.

1. Pour silver solution into closed 25 ml stopcock buret⁵ (stand⁶ and clamp⁷). Illustration
2. Melt Gelatin A to 40°C in 60°C waterbath, stirring gently with a clean plastic spoon.
3. Add a magnetic stirring bar and start a vigorous vortex in the center of the beaker.
4. Add the salts in the order listed, stirring to dissolve after each addition.
5. When the temperature of the salted gelatin reaches 50°C go to red darkroom safelight illumination⁸ and position the buret over the gelatin.
6. Turn off the heat on the hot plate.
7. Set a darkroom timer for 10 minutes.
8. Open the buret (contents should empty in 45-60 seconds.)
9. Continue stirring for 4 minutes, then slowly add Gelatin B, mixing it in with the help of a plastic spoon.
10. Finish out the ten minutes with the magnetic stirring bar.
11. Remove the beaker from the waterbath. Wipe off the water with a clean towel.
12. Slowly pour the emulsion through a stacked set of cone-shaped gold mesh coffee filters (3 to 5), set in a funnel over a clean 400 ml beaker.
13. When the emulsion has filtered through, divide into two pint-size canning jars.
14. Cover each jar with a piece of plastic wrap secured by the canning lid band or a tight rubber band. (Don’t allow metal to come in contact with the emulsion.)
15. Set each jar in its own light-tight container in an inch or two of ice water.
16. Secure container lids and place in refrigerator for at least 8 hours, but not more than one week.

PART TWO:

Preheat waterbath on stirring hot plate to 50°C.

Remove one light-tight container from refrigerator. Place on a coffee mug heater, or similar (~60°C) for one hour.

Go to red safelight.

1. Open the container and place the canning jar of emulsion (remove plastic wrap) in the preheated waterbath with a thermometer.
2. Stirring gently with a plastic spoon, melt the emulsion and bring it to 40°C.
3. Pull the canning jar out to the waterbath and pour the emulsion through a gold mesh coffee filter into a 250 or 400 ml beaker. Drop in a stirring bar.
4. Place the beaker in the waterbath and start slow magnetic stirring.
5. For dry paper coating, add 10 ml room temperature distilled water.
6. Bring the temperature of the emulsion up to 45°C.
7. Set a darkroom timer for 5 minutes.
8. Add 12 drops 1% KI solution. Stir 2 minutes.
9. Add 12 drops Photoflo 600 (or Daniel Smith Acrylic Flow Releaser⁹, diluted 2:1 with water, or to best effect).
10. Add 10 drops glyoxal.
11. Continue stirring for the remainder of the 5 minutes.
12. Strain through a gold mesh coffee filter.

Cool to coating temperature and coat paper as usual. here