Black and White Photography Test Strips
The test strip is either a full sheet of paper or a strip of the photographic paper. The paper is placed on the easel and preferably secured. The timer is set to an arbitrary figure, which is known by experience of using the enlarger. In addition the time interval is dependant on the magnification, ie the distance from the lamp to the paper (inverse square law). On my enlarger at f11 or f8 a test strip interval of 5 second when enlarging a 645 negative to 10"x8" is appropriate. In the case of this example, grade 5 paper was used which requires more processing, and greater enlargement was required, so 15 second was used. Set the timer to 15 seconds and give the test strip one exposure cycle. When the light goes out, take a piece of cardboard or similar and cover ¾ of the test strip. Start the enlarger again and wait for the cycle to finish. Repeat this until the last quarter is covered. This will give a test strip, which has 4 zones at 15, 30, 45 and 60 seconds. Here is a picture of the completed strip, although prior to development there is no visible image.
Developer - reacts with the latent image to produce the black silver which forms the visible image. The time spent in the tray should be as per the manufacturers instructions, for Ilford multi-grade developer with resin-coated paper this is about 2 minutes. The longer the print stays in the developer, the darker the print becomes, however, the results tail off after a while.
Stop - The stop solution arrests the development of the image.
Fix - The fix neutralises the effects of the developer and the paper. The fix also stabilises the paper and renders the emulsion inert. Improper fixing will leave archival problems and will also be apparent if toning is used. Normally about 3-5 minutes in the fix is sufficient for resin coated papers.
The washing cycle follows the fix stage, washing can be completed in cheap tray as per the Patterson print washer (pictured) or in the much better archival washers manufactured by Nova. The wash cycle time is dependant on the type of paper used. Resin coated papers only require a few minutes, and in fact extended washing will damage the paper. The recommended wash time for Kentmere Art Classic (heavyweight fibre based paper) is 30-40 minutes.
Print Drying is an important part of the process, resin coated papers are very easy to dry, they just dry naturally in a rack as pictured:
Print Drying Rack
Fibre based papers need to be dried on a drying mesh and then on a print glazer/dryer.
These are quite expensive and not normally used by amateurs and home photographers.
It is obvious to see why the majority of photographers prefer resin-coated paper
to fibre based, as every step of the process is more difficult and or more time
consuming. The purist however will always choose the fibre based paper.
From this position we can analyse the strip and say that the print should be exposed for 60 seconds. A full sheet of paper is then loaded into the easel and exposed for 60 seconds. The timer would need to be programmed to reflect the new time. The process of exposure, development, stopping, fixing and washing is repeated exactly as when producing the test strip.