Dish Processing
Tray Bon!
In these days of instant this-and-that and auto everything else there has to be a special reason for tray processing to still be so commonplace in the darkroom. True, there are alternative methods of developing paper once it's been exposed... in deep tanks, slot tanks, rotary drum or roller-transport processors, for example. However, they all have certain drawbacks depending on your methods of working and the amount of printing you do.
For black-and-white work tray processing has two main advantages over all other methods... it's cheap and you can see what's happening. But if you don't find either of these reasons important then automatic or machine processing is your obvious answer... unless you prefer pushing pixels on a computer screen! ;-(
Step by Step...
With print processing there are four basic liquid steps to take your exposed paper through... developer, short stop, fix and wash. Print trays are needed for at least the first three of these steps. In the darkroom it's important to standardise on equipment. If you shoot a lot of film you will make a lot of contact sheets... and these are usually made on 10 x 8 inch paper. You will probably make a lot of prints on 10 x 8 paper too... but don't buy 10 x 8 trays unless your bench space is very restricted, buy the next size up at 12 x 10 because there's nothing worse than trying to pick a print from a tray when you can't pinch the edge with print tongs.
With tray processing, as with any photographic process, consistency is the keyword. You will repeatedly make poor prints by using slapdash methods... but you can make good prints time after time by utilising a carefully controlled technique.
Believe what the chemical manufacturers write... their instructions will indicate the optimum dilution, usable temperature, immersion time and life of chemistry... four obvious pointers often ignored in practice! A developer that should be diluted at 1:9 will give the best results and economy at that dilution... it will probably work at any dilution between 1:1 and 1:20 but will be wasteful, less controllable and may produce poor print contrast.
When a glowing print emerges from the developer don't lose it by not fixing it properly. Fixers are very efficient... too weak or exhausted a solution will result in print fading at a later date. Too strong a dilution and a print will have to be washed much longer for permanence.
It's important to watch chemical temperatures too... trays present a large surface area and their contents can cool quickly unless the ambient room temperature is the same... ideally 20 degrees C.
Time Control
Then there's the time factor... the most abused variable in tray processing. Many printers (pros too) see a print develop nicely and pull it after perhaps thirty seconds when the recommended time is sixty... which means the print was over-exposed... and under-development simply won't produce a great print. On the other hand if a print takes two minutes to fully develop then the print has probably been under-exposed.
You'll find that under-developing or "snatching" a print before the recommended time has elapsed will only produce a muddy print. Over-developing or "stewing" a print for longer than recommended will add initially add some contrast... but then veil the light-toned areas resulting in a loss of contrast. There's simply no substitute for correct exposure of a negative followed by correct development of the print.
Another problem with chemicals in open trays is cross-contamination. This happens when trays are too close together... and although it would take an appreciable amount of developer to neutralise the stop-bath, a small splash of stop plays havoc with a developer. When initially preparing chemicals mix the developer first, then the stop and fix. It's better to use two graduates... one marked for alkaline developers the other for acid stop and fixers... and your processing trays should be marked in the same way.
Although tray processing is a simple and repetitive darkroom task there's a correct way of doing it... and even after years of practice there's a certain feeling of satisfaction to be had watching the image emerge from a blank sheet of paper. But there are two schools of thought on this... one says that you should immerse the paper upside down leaving the image to develop for the recommended time before transferring it to the stop. Only after fixing it should you look at the print under white lighting. If your printing technique is a hit-and-miss affair then this method will take a lot of time! The other school of thought advocates watching the image appear magically before your very eyes... and for many this is what printing is largely about.
Both methods are valid and really depend on what you are doing. If you are printing several images from the same negative and have made a correct proof print you should be able to develop the rest without looking at them. You can expose all the prints in a single batch, store them in a light-tight box, then process together.
Visual Appraisal
Of course visual appraisal of a print's development while it's in the tray is purely guesswork. For a start all print tones appear considerably darker when viewed under the red or amber safelight conditions of a darkroom.
Secondly, prints show slightly less tonal contrast when dry. This particularly affects highlight areas which can look sparkling white when wet but become slightly greyer on drying. Deep, rich blacks lose some of their intensity too... an after-effect known as "dry down."
By using oversized trays you can immerse the first sheet upside down into the developer followed by more sheets at ten second intervals and at right-angles to each other. Whilst agitating the tray with one hand you pick out the bottom print, place it on top of the pile and so on. A pencil on the back of the first print will tell you when it's been through the rotation cycle. Batch processing used to be commonplace with fibre-based papers which take up to three minutes to develop fully... but modern resin-coated papers develop in around one minute making this technique rather unnecessary.
For single print making I prefer to watch the image emerge and "tweak" if necessary... tweaking is not a substitute for "dodging out" or "burning in" of small areas of a print but it can be used as a fine control. If a small area of the print is appearing to develop too dark your finger can be placed on that spot to stop fresh developer acting on the emulsion. You can also dab a neat developer impregnated cotton bud or blow through a straw onto an area which is not developing quickly enough... the warmth activates the print locally.
Emergence Factor
Some who watch prints develop use a timing control known as the "emergence factor"... which is the time it takes for the first image tones to appear. If a paper has a development time of three minutes and an emergence time of thirty seconds then the emergence factor is x6. If this time increases towards the end of a printing session then the developer solution is becoming exhausted and needs replacing. If the emergence time is noticeably shorter then the print has probably been grossly overexposed. Of course these times vary with the paper and developer type.
As long as the print is constantly agitated in the chemicals the actual process of developing, stopping and fixing is simple to do. Results are guaranteed every time providing the dilution, temperature and time factors are adhered to. But the process doesn't end there. All your efforts will be wasted if the print is not washed properly to eliminate residual traces of acid fix.
Users of traditional fibre-based papers, which are still preferred by many for making exhibition and folio prints, should adopt a more archival processing technique in print making. This requires a greater worktop area because of the extra processes and trays involved.
It's good practice to use two fixing baths. Prints are fixed for half the recommended time in the first fixer and half the time in the second. After a while the first bath, which does most of the work, will become exhausted and should be thrown away. The second fixing bath which is still quite fresh then becomes the first bath and a new batch of fixer is mixed for the new second bath. With this method the final fixer bath used for each print is always working efficiently. Fixing is followed by a short rinse, then an optional period in a hypo clearing agent, followed by washing in several changes of water (another subject for another day).
Modern rapid fixers are usually based on ammonium thiosulphate which only need about 30 seconds to remove any silver halides not reduced to metallic silver during development. To leave a print in a rapid fixer for any longer is counter productive because it takes more rinse water and time to wash thoroughly and the fix acts as a slight bleaching agent on the image tones... and any residual fixer left in a print will cause discolouration at a later date. Basically, prints should not sit in the fix tray awaiting washing.
Paper Swelling
If prints are left wet for too long the paper base swells. With fibre-based papers this can cause breakage of the emulsion surface, kinks in the paper from careless handling and wavy edges to the dry print. Resin-coated papers also suffer with water seeping into the paper base between the polythene outer surfaces. In extreme cases the print will peel from the backing. Don't let any of this put you off darkroom work... black-and-white printing "in the open" is one of the real pleasures of traditional photography.
But what's available? Will any tray do? Are there any special features to look for? For a start buying three trays in different colours is a good idea. Using different trays for different chemicals avoids any cross-contamination problems. Good developer trays have ridges along the bottom so that you can get print tongs under the paper to move it around... and the grooves allow fresh chemistry to circulate better. Although pet shop suppliers are sometimes recommended for cheap alternatives to proper darkroom trays they're a false economy. You'll experience many a potential masterpiece sticking face down to the smooth bottom of a kitty-litter tray... it's a bad practice and will strain your relationship with little Mimi!
9:17:44 PM 
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