36 EMULSION WORK - Silverprint

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ALTERNATIVE PROCESSES BROMOIL The Bromoil Process In 1907, working from the research of Howard Farmer and E.J. Wall, C. Welbourne Piper publicised the working details of a process that produced an inked image from a silver bromide paper print. A non-supercoated paper print is treated in a dichromated bleach solution, converting the silver image back into silver bromide. The bleaching bath also hardens or tans the gelatine in proportion to the amount of silver present. The print is washed in water, swelling the gelatine into a relief matrix that will accept greasy ink in the shadow and mid-tone areas, but repel it in the highlights (where the water content is highest). Once the matrix has been drained and blotted, the original photographic image can be inked up with a large blunt-cut brush, or small rubber brayer. Bromoil transfer is a variant of the above wherein the inked matrix is printed onto a second sheet of paper. A mangle press or the back of a spoon can be used for the transfer, which is suitable for colour work as a series of selective matrices can be printed in register to produce a coloured image. Materials Paper- Kentmere Art Document bromide enlarging paper, contrast grades 2 or 3 Print the bromide print for both highlight and shadow detail, printing somewhat darker and flatter than usual. Develop, wash (do not use stop bath) and fix using the solutions below, and wash thoroughly. Developer - use a developer having a minimal hardening effect on the gelatine of the paper: Amidol and Sodium Sulphite, or: Kodak Dektol diluted 1 part developer to 10 parts water. Fixer - without hardeners. A basic fix normally contains acidifiers but no hardeners. If in doubt, try Tetenal Variofix, the new powder packing ‘Silverfix’, or a 100 grams per litre solution of plain hypo (sodium thiosulphate) with 5 grams / litre of added sodium bisulphite or sodium metabisulphite. These fixers can also be used to fix the bleached print Bromoil Bleaching Bath Copper sulphate15 g Potassium bromide 15 g Potassium dichromate 1 g Mix in 375ml. distilled water, then top up with water to make 500ml. stock solution. Store in a dark brown bottle, away from heat and light. Dilute for use: 1 part stock to 3 parts water. Bleach in the bleaching bath until the image is a faint beige colour, and leave in the bath for half again as long. Wash thoroughly and fix as usual. A grey-ish image should be barely visible. Dry the print, and store away from light. Inking Adana letterpress inks or Charbonnel litho. inks. Add French chalk to increase tacky consistency, a solvent is extra-refined lighter fuel. Soak the print in water at 20°C for at least 10 minutes. Place the print face up on a paper towel to blot water off the back, then face up on a smooth waterproof surface. A tilted sheet of melamine or plexiglass is suitable as an easel. Blott the surface of the print (gently) with a damp chamois. Work over the print with brayer, covering entire surface quickly then more carefully redistributing and clearing highlights and mid-tones. Or, with a brush, start with a hard consistency of litho ink and hop this onto the entire surface of the print. Work over the print with shorter hopping strokes to redistribute the ink from the highlight to shadow areas. Once inked, the print will take about 24 hours to dry thoroughly. Bromoil Brushes These are British made to original specifications, and are produced in 2 qualities. Both are available in a range of 5 sizes. These are basic quality, ie without copper wire tying, set in plain metal ferrule. 12 816 No 2 Bromoil Brush 3.28 3.85 22 442 No 6 Bromoil Brush 3.73 4.38 22 479 No 8 Bromoil Brush 4.75 5.58 22 481 No 10 Bromoil Brush 5.94 6.98 22 494 No 12 Bromoil Brush 6.98 8.20 Bromoil Video 39 The roots of the process can be traced back to the early 1800’s, but it was not until the early 20’th century that the technique was perfected, reaching its zenith of popularity in the 1920’s and 1930’s. The late Norman Gryspeerdt made bromoil pictures for over 50 years, and was one of the most significant exponents of this technique world wide.In this video he describes and demonstrates the technique, so that by following the various steps the photographer will quickly obtain a working knowledge of the process and be ready to commence making pictures. Stocked in DVD format. 21 883 Gryspeerdt Bromoil DVD 16.96 19.93 Bromoil Kit The Fotospeed Bromoil Kit contains : Bleach Tanning Chemistry, Bromoil Paper 8x10in 10 sheets (a non supercoated, low contrast paper on a D/W fibre base - specifically made for the Bromoil process), one real Bromoil brush, 4 Inks (Black, Yellow, Magenta and Cyan), Inking tile, gloves and full detailed instructions. Bromoil Paper in 12x16(10) and 16x20(10), Inks (black, yellow, magenta, cyan), brushes (in varying sizes) and chemistry are available separately. 23 842 Bromoil Kit 34.00 39.95 27 694 Black Ink 30ml 4.32 5.08 27 701 Yellow Ink 30ml 4.32 5.08 27 726 Magenta Ink 30ml 4.32 5.08 27 738 Cyan Ink 30ml 4.32 5.08 27 740 Bromoil Chemical Pack 4 l. 9.18 10.79 Paper for Bromoil The most suitable paper is one that we originally comissioned as a special making for the process, then retitled as the new Kentmere Document Art, and now about to be discontinued! Check with us or our website for remaining stock of this paper.See page 5. The Art of Bromoil & Transfer Written by the Canadian Bromoil expert David Lewis, this is a beautifully illustrated self-published book delving into all aspects of this resurging medium. As well as extensive details of working methods, contains many portfolio examples reproduced by full colour printing. 1994 David W. Lewis, Hardback, 120 pages 25 889 The Art of Bromoil & Transfer 25.00
ALTERNATIVE PROCESSES CYANOTYPE New CYANOTYPE Invented by Sir John Herschel in 1841, this simple process gives a continuous-tone image of Prussian Blue using a sensitising solution of Ammonium Ferric Citrate and Potassium Ferricyanide. These iron salts, when exposed to natural or artificial ultraviolet light, are reduced to their ferrous state, producing a high contrast blue image when oxidised. Oxidation is hastened by immersion in running water, which also washes away the unused iron salts. The Process Solution A 65 g Ammonium ferric citrate (green) in distilled water to make 250ml total. Solution B 23 g Potassium ferricyanide in distilled water to make 250ml total. Note : distilled water is more commonly known as 'purified water'. Store solutions separately in brown glass bottles, away from light. Filter before use, and mix in equal proportions A to B. Printing Paper: For all alternative processes high quality art paper such as those used in printmaking or watercolour work are most suitable. Somerset Satin and Waterford Satin are good papers to start with, however it is advisable to make tests to find a paper to suit your requirements. Coat in subdued tungsten light, and dry away from light and heat. Print by contact (in a printing frame with a full sized negative) in sunlight or by an ultra-violet light source until the shadows look bronzed. Allow at least one stop over-exposure to compensate for loss of density during processing. Development Immerse in running water, and wash until the chartreuse stain of the ferric ammonium citrate has completely disappeared. Take care to avoid excessive washing as this will tend to wash out the image. THE CYANOTYPE KIT - Contains: Sensitiser 50ml (sufficient for 40 - 8x10in applications), Syringe 2ml, Fabriano paper 5 sheets 8x10in, Two glass coating rods 4in and 8in, Protective gloves and full detailed instructions for use. Sensitiser, Glass coating rods and Hypo are available separately along with traditional contact frames with hinged backs in 8x10in and 12x16in. Raw chemistry is available on request - please phone. Cyanotype is in a single solution, and is an updated version of the original process. Using Ammonium Ferric Oxalate to give a good blue that does not wash out, this solution is twice as sensitive to UV as the traditional version. Development in water and citric acid can be used to manipulate contrast. All images are made by the contact system, where the image depends on a negative of the appropriate size. 15 670 New Cyanotype Kit 28.98 34.05 75 872 New Cyanotype Sensitiser [included in kit] 11.41 13.40 GUM BICHROMATE In 1839, Mungo Ponton published a paper on the light sensitive properties of chromates. These are strong alkaline compounds that are available today as potassium or ammonium dichromate (bichromate is the older and more common term). In 1852, Fox Talbot used animal gelatine in combination with dichromate. He observed that the dichromated colloid hardened in proportion to its exposure to sunlight, and applied the principle to an early photogravure process. This work formed the basis for many later photographic and photomechanical processes. In 1894, A. Rouille-Ladevez redefined the process, producing prints for an exhibition at the Photo- Club de Paris. His work inspired photographers whose pictorial work derived from Impressionism in fine art, and great use was made of the gum bichromate process as a method of producing the painterly images so characteristic of turn-of-the-century art photography. Materials Gum arabic; Available as prepared liquid gum arabic (avoid acid preservatives) or mix dry gum (acacia) at 1 part to 3 parts water. Dissolve (overnight), strain, and add optional preservative (phenol based such as thymol, never formalin or formaldehyde) Pigment; Water colour for transparency, or designers gouache or casein for more opacity. Powdered pigment should be ground with a small quantity of liquid gum arabic. Potassium Dichromate (bichromate) Ammonium Dichromate (bichromate) is capable of a more saturated solution, decreasing exposure time, but giving some problems of exposure control. Paper; a good quality, sized, art paper is recommended. The Process Potassium dichromate: make a 10% saturated solution (10g to 100ml distilled water) The solution will keep in the dark. If crystals form during storage, redissolve by warming the bottle. Mix the gum solution and sensitiser in equal parts. Use as soon as possible. Add to prepared pigment. Coat paper with a soft, broad brush, and allow to dry away from light and heat. The prepared paper will keep for several days in the dark, but works best when used as soon as possible. Expose the paper to sunlight or a mercury vapour lamp by contact printing under a negative. Exposure time will depend on density of negative and type of light source, but always look for a brown print-out in the shadows and the start of the mid-tones. The colour of the pigment in the coating will also affect exposure time: blue and green requiring less time than red or yellow. 'Develop' the print in a bath of tepid water. Slide the print into the water (face down). Soak (a few minutes to several hours, depending on exposure). Unexposed gum will dissolve, while gum hardened by the action of light and chromate will remain. Gum coating can then be removed locally by the application of a stream of water or gentle brushing. Flatten the wet print against a tilted, waterproof board to dry. The gum print can be overprinted by recoating (once dry), re-exposing and developing. Staining of pigment in the highlights can be minimised by the application of paper size, and the dichromate stain can be removed in a 5% potassium alum bath, or by re-soaking the finished, dried print in warm water. Gum Bichromate Kit More correctly ‘dichromate’, but the old name isn’t going to go away, the Fotospeed Gum Bichromate provides an ‘out of the box’ introduction to this fascinating process, yielding the most ‘painterly’ effects of any of the alternative processes.The kit contains: sensitising & clearing solution: half-tone solution: shadow solution: watercolours in tubes, Lamp Black, Payners grey & Burnt Umber. Also included are a pair of surgical gloves, and 10 sheets of HP watercolour paper. Concise instructions are included. 48 837 Salt Printing Kit 34.04 40.00 40
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36 EMULSION WORK - Silverprint

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