CHAPTER 7
making unwashed silver cloro-bromide gelatine emulsions

for alternative photography are given here. clorobromide gelatine silver emulsion give a warm sepia tone and all particulars are described as well of formulas of how to make liquid light photographic sensitive silver emulsion. saul bolanos is the author of this book all about photograhic emulsions cloro-bromide silver gelatine positive emulsions. this is chapter 7.,

Unwashed Positive # 2
Emulsions Silver Chloride & Rapid Silver Chloro-Bromide Emulsion.Unwashed silver gelatin emulsions are very convenient and can be prepared in two easy steps as follows: 1) Precipitation:
or mixing the silver solution with the gelatine salts solution in darkroom by bright red, yellow or orange light. 2) Ripening: Heating the mixed emulsion in a water bath at 55c For a specified time, 1 to 4 hours 3) Coating: Coating the finished emulsion on absorbent material like pure fiber paper, wood or cloth, etc Because there is no ammonia to wash out the following emulsions do not require shredding and washing out the excess soluble halides or soluble nitrates as long as they are coated on absorbent surfaces like fiber paper. (Also wood, cloth etc) On absorbent surfaces the soluble nitrates and excess halides will sink into the fibers of the paper in 24 to 48 hours after coating. When this happens the coated emulsion will have its acquired speed and contrast.
If tested immediately after coating and forced dried by a current of cold air, speed and contrast will be lower. If exposed and developed after 24-72 hours after the coating has dried on the paper or material, contrast and speed will be higher than the same coating processed immediately after drying. On Recently coated and dried surfaces; the emulsion will feel a little sticky to the fingers. If the recently coated emulsion is dried first with cold air as to drive out most of its water, and afterwards with warm air (from a blow dryer or hair gun) the fresh coated surface will loose its stickiness quickly but this will also occur spontaneously in 24 to 48 hours after coating on paper. This stickiness is due to the nitrates which attract humidity from the air and are still floating on in the surface even after the emulsion is dried. If the unwashed emulsion was coated on glass; these salts would not sink and would crystallize on the surface. Hygroscopic and sticky Potassium and sodium nitrate are formed as byproducts in the formulas given here.
The excess halides like sodium chloride or potassium bromide, still kept by the unwashed emulsion as by products after precipitation are not sticky, these last soluble salts will also be present on a great excess on the surface of the recently coated unwashed emulsion, but they will also sink into the fibers gradually, when they do, the speed of the emulsion, (that is its light sensitivity, will increase.) These soluble halides are usually eliminated in “washed emulsion” during the process of washing the emulsion for the purpose of increasing its speed. Washing also gets rid of the soluble nitrates necessary for coating the emulsion on impervious materials like glass or celluloid. As otherwise without washing, as mentioned earlier, these nitrates would crystallize on its surface. Notes on contrast below apply to all unwashed cloro-bromide emulsions and in a great measure also to chloride unwashed emulsions.
IMPORTANT FOR HIGHER CONTRAST
-At the end of ripening , after adding finals, Leave the liquid uncoated liquid emulsion at room temperature ( 18-27c) for at least 48-72 hours, at the end of that time, refrigerate if it is to be kept for a long time uncoated in liquid form. Or coat it to test it on paper. In this way Contrast should be higher than the same emulsion immediately coated when recently made and without leaving it to “mature” at room temp for a few days.
The recently made emulsion can be coated and processed immediately for testing of course; in which case as said above, - its final contrast will not be evident until about 24-72 hrs after coat has dried on the paper. NOTE: If left to mature at room temp for a few days as directed, the coated material usually shows its final contrast much sooner when coat has dried and it is higher than same emulsion not matured 72 hrs.
Weights of Alkali halide Required To Saturate 1 gram of Silver Nitrate:
Sodium Chloride        0.344   grams
Ammonium Chloride 0.315   grams
Potassium Bromide   0.70     grams
Ammonium Bromide 0.576   grams
Chloro- Bromide Positive Emulsion # 2
Formula As Given in the paid version Can Yield Warm Tones Easily.The real difficulty in preparing an unwashed silver chloro-bromide emulsions is to obtain a speed high enough for enlarging and also good contrast, clean whites deep blacks and above all: warm tones. High contrast emulsions are difficult to make without ammonia. But if ammonia was present, to get rid of it , the emulsion would have to be washed because if left on the emulsion it would generate fog and brown stains,
At the my research labs, after a great number of trials, I did work out the following formula which assures high contrast and good speed. Even with the best of gelatines chloro-bromide emulsion with high contrast and excellent blacks can not be made by simply adding the silver solution directly into the gelatine salts solutions as is the usual process recommended in most emulsion making books. 



Potassium or ammonium bromide is used in combination with sodium chloride (ordinary table salt) to make chloro-bromide emulsions. The more chloride the higher the contrast but the lower the speed. The more bromide is used, the higher the speed and the lower the contrast. The following chloro-bromide emulsion formula has equal molecular equivalents in both silver halides, that means that the chlorides in proportion to the bromides; -in the finished emulsion will be 50% silver chloride and 50% silver bromide suspended in the gelatine. These fact alone assures very warm tones on development, from sepias to warm blacks. Or even plain blacks if that is the tone wanted. Iodides in the formula would give a lot more speed, but will kill its beautiful warm tones. Sensitivity will depend on the type of gelatine used. Active gelatines yield 200 % more speed with this formula than gelatines of normal or medium activity. The only way to test any gelatine is by actually making the emulsion. Food grade gelatine in sheet or leaf form is recommended (never use food grade gelatine in powder form). “Photo grade” gelatine in powder or leaf form is superior to edible gelatine but is not absolutely necessary. Another advantage of this particular formula is that it yields excellent results with any type of Food grade (edible) gelatine as long as it is in leaf or sheet form. . Even type 4 “inert” type of gelatines will yield good strong blacks without out having to add sulphur to them. So good results are guaranteed with “any type” of gelatine in “Leaf ” form.

Relative Normal Development time for different Positive emulsions at 20c Enlarging Speed or Sensitivity CHLORO-BROMIDE POSITIVE EMULSION # 2 If emulsion is ripened to high sensitivity by application of heat as instructed; (3 hours / 55c) Assuming a 3 x enlargement is being made from a normal contrast bw silver negative; -with the enlarging lens open at f 4 and a 100 w incandescent ordinary bulb as the light source: Exposure will be about 10 seconds with gelatine of medium activity and about 2.5 seconds with fast active gelatines. Regardless of the gelatine used; -Speed will triple on storage. The coated emulsion after about a year, (kept in total darkness sealed inside a plastic bag at normal room temperature not above 27c, will have a speed of about 1.25 seconds for the medium active gelatine and less than half a second if made with the very active one. In both cases with superb high contrast, the whites will be clean without fog and the blacks vibrant and alive. (If properly stored)
Chloro- Bromide Unwashed
Positive Emulsion # 2


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NOW REFER To GRAPHIC STEPS
Leave Finished uncoated emulsion at room temp at least 12 hrs, before shocking it in the cold of refrigerator. Chloro- Bromide Un washed Rapid Positive Emulsion # 2 Text Instructions All steps in darkroom under Red or Orange illumination. Use a 1 liter glass bowl for the salts solution. Soak the gelatine in the salts solution at room temperature for at least 15 minutes before dissolving it completely (at least 10 minutes) in a hot water bath at 55c. While salts solution is in hot water bath add all of the silver sol B to the salts sol A rapidly in less than 10 seconds (preferably 5 seconds.)
While at the same time stirring the salts solution briskly all the time. Stir the salts solution with a plastic spoon or better still with stainless steel wire beater At the end of precipitation continue stirring with the wire beater for 60 seconds. at the end of that time keep glass bowl containing the emulsion in hot water bath carefully maintained at 55c (131 f) leave there for 10 minutes before adding solution C, add sol C, rapidly also in less than 5 seconds while agitating continuously all the time. After adding all of sol C, continue agitating emulsion with the wire beater for 60 seconds more. At the end of this time, precipitation is complete. Now transfer the mixed emulsion from the glass bowl to a 0.75-1 liter glass jar which must have a lid. After transferring emulsion into the jar, put a plastic spoon inside jar for agitation later. Place lid on jar so vapor will not escape and so emulsion will keep a constant volume all throughout the ripening time. Keep the emulsion inside jar for 60 minutes at 55c; agitate emulsion for 15 seconds every 15 minutes during those 60 minutes of ripening time. Agitate with the plastic spoon previously left inside jar. Do not forget to put cap on emulsion jar every time after agitation. At the end of 60 minutes 55c ripening time, add to the melted emulsion the dry gelatine D. if in leaf form, previously cut in very small pieces.
Continue stirring emulsion for 10 minutes until all the gelatine has dissolved. You can probe with your fingers, (emulsion is not toxic) un-dissolved gelatine will always tend to stick to the walls of the glass jar and will eventually melt in 10-15 minutes. Once gelatine has dissolved continue heating the emulsion in the water bath at 55c (131 f) for two more hours. Every 15 minutes during that time, agitate emulsion during 10 seconds to keep all silver suspended .This agitation will also completely dissolve any remaining solid particles of gelatine. Keep lid enclosing emulsion jar all the time that emulsion is not being agitated. At the end of 2 hours 55c, (totaling now a heat time of about 3 hours 15 m, add finals solution E, as given,
Plus add water to bring final volume to a total of 500 ml for a normal 8% gel concentration; this make it thin for coating of large areas, or to 400 ml, for a 10 % thicker gel concentration for coating small objects or small areas. Emulsion is now finished. After cooling to about 35c it can be coated on paper and tested. To disperse any doubts "STUDY" Graphic Steps. Contrast Speed and Stability
Adding potassium bromide as stabilizer to the recently made emulsion immediately at the end of ripening, may drop speed by 100 % and also lower contrast, this will not happen if emulsion is first matured at room temp, this maturing increases contrast notably. To do this -At the end of ripening , after adding finals, Leave liquid uncoated emulsion at room temperature ( 18-27c) for at least 48-72 hours, at the end of that time, the stabilizer may be added and Refrigerate if it is to be kept for a long time uncoated in liquid form. If left to mature at room temp for a few days as directed, the coated material usually shows its final contrast much sooner when coat has dried and it is higher than same emulsion not matured 72 hrs.
Coated on chemically inert materials, like 100 % cotton or rag watercolor paper , Without stabilizer (stored below 27c) Coated emulsion will gain from 5 -10 times more speed in about 1 year, but contrast will not drop nor fog will appear. In equal conditions if coated emulsion is stored at a colder temp (about 5-10c) under refrigeration; Original speed should remain without change, and will keep for many years without fog.
Tones Black to Sepias.
When the developer is diluted, prolonging developing time accordingly while at the same time increasing exposure, the image tones may be made to vary any where from brown black, chocolate black to even solid sepias, this last tone is easier to obtain if a little extra potassium bromide is added to the diluted developer. Adding a little citric acid to much diluted developer will also impart particular extra warm tones on increased exposure and development time. The type of developer will also affect the tones. Toning the image developed to black tones in hypo alum direct sepia toner or any of the toners given in chapter 11 will furnish extra-ordinary extremely rich Sepias. The Best by a silver process.
Relative Speed and Tones :
If tones are Compared side by side , on prints made with a pure silver bromide emulsion like my # 1 ammonia formula, and prints made with this chloro-bromide emulsion; The first will be blue black and the second warm brown black to neutral black with undiluted developer. All conditions being equal and same type of gelatine, the first will print by enlargement with a relative exposure of about 5 seconds and the second with 15- 20 seconds exposure.
PAPER DEVELOPER D 72
This developer is identical a kodak’s Dektol, it can also substitute Ilford’s Bromophen or Agfa’s Neutol paper developers.

Water about 50c ( 125 f) 500 ml
Metol (or kodak’s Elon) 3 grams
sodium sulphite anhydrous 45 grams
Hydroquinone 12 grams
sodium carbonate monohydrated 80 grams
( If anhydrous use 67 grams)
Potassium bromide 2 grams
add cold water to make total 1000 ml
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For use, dilute with 2 parts water, For Black Tones expose to develop from 45 to 60 seconds at 20c ( 68 f) With emulsion correctly made there should be no fog even in 2 m development time at 20cFor warm blacks dilute with 6 parts water, expose to develop in about 2 m For brown blacks add 1ml of 10% potassium bromide to 250 ml developer diluted 1:10 with water/ increase exposure to develop in 3-5 m.
Processing
1. DEVELOP see above
2. STOP BATH
Transfer to a 1 % acetic acid stop bath for 30 seconds. If there is damage here or during washing use Bor Alum Hardening stop bath (which see) for 30-60 secs, With this excellent stop bath, a plain non hardening fixing bath can be used below.
3. FIX
for 10 minutes In a hardening fixer with frequent agitation. For Archival Permanency: 10 min / 2 baths First Bath: 5 minutes this bath can be a used bath (but not overworked) Second Bath: 5 minutes, bath must be fresh and unused.
4. WASH 30 minutes to 1 hour (for heavy papers) in gently running water. FOR DEVELOPING WITH COFFEE ( MY INVENTION) SEE CHAPTER 13.
Coating Paper
emulsion may be coated directly on watercolor fiber paper, For better blacks Apply 2 brush coats drying apply 3 thin brush coats of emulsion (see coating paper Emulsion Capacity (Brush Coated) 1 Liter will cover about 80 sheets of fiber paper size (20 x 25 cm) 8 x10 in.
Extra Rapid Chloro-Bromide Unwashed Positive Emulsion # 3
Formula To make 250 ml of finished emulsion.

This emulsion since it is richer in silver; it has more covering power and it is about 100% more rapid than unwashed emulsion # 2 . Made with same gelatine, it has about similar speed and contrast as ammonia “washed” emulsion # 1. Contrast is about grade 3, process in same way as chloro- bromide #2.
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A. Salts Solution Heated to 45c (113 f )
Dissolve in order given
Distilled Water....... 100 ml
Citric Acid .........    1 gram
Sodium chloride (ordinary kitchen salt)... 0.5 gram
potassium bromide 0 grams
flavorless and colorless gelatine ....3.5 grams
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B. Silver Solution, use at room temperature
Distilled Water ................. 100 ml
Silver Nitrate ....................10 grams
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C. extra Salt Solution: : use very hot water to dissolve
Distilled Water ............ 25 ml
Sodium chloride (ordinary kitchen salt) 4.5 grams.
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D. extra gelatine:
( add dry, if leaf form / cut in pieces)
flavorless and colorless gelatine .... 10 grams
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E. Finals:
Add all of the ingredients below at the end of ripening (2 hr 10 min /45c) before coating. Add one at the time in order given with good agitation after each addition, quantas below are for all 250 ml of to prevent frilling of gelatine  emulsion on glass plates or damage on paper during processing:
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Emulsion Gelatine Hardener
5 % potassium Alum solution. ...... 4 ml
As coating aid to make Emulsion flow and Spread easy :
Ethyl Alcohol ( the type people drink ) 10 ml
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Antiseptic
to keep uncoated emulsion in liquid form under refrigeration
for 12 months with out spoiling:
10 % ( ethyl ) alcoholic solution of Salicylic Acid: ...5 ml
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Stabilizer
10 % solution of Potassium Bromide: 1 ml
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Add this stabilizer only if uncoated finished emulsion is “matured“ by leaving at room temp ( 18-27c )  in liquid form (not under refrigeration) for at least 3 days after making it. Otherwise speed and contrast will drop if stabilizer is added immediately to the recently made emulsion at the end of ripening. Without  stabilizer, the Coated paper will keep much more than 1 year without fog, ( stored not above 27c)

EMULSION DATA
1. 170 % Halide (salt) in excess
2. Ratio Ag / Gel 1:2
3. silver bromide to silver chloride 1:1
4. Ripening temp: minimum 2 hours/ 45 c
for extra speed and contrast grade 3.0

Note: due to a higher concentration of reactants,  this emulsion ripens at a much faster rate. Do not ripen higher than 45c , in order to keep warm tones.