Split grade printing is a technique used to produce a b&w darkroom print with multi grade enlarging paper. It involves making two separate exposures to the same sheet of paper using both a hard and a soft grade filter, usually grade 5 and grade 0. But this choice can be any appropriate combination of filters that suit the image.
In this article I'll explain two methods of arriving at the exposure times for both the hard and soft grade exposures, an overview of how to dodge and burn when using split grading and lastly my own approach to the technique.
There is a belief among some printers that split grading can unlock hidden grades within multi grade paper, that is not a notion that I subscribe to but I do think the technique of split grade printing can help with negatives that might require complex dodging and burning in order to produce a satisfactory print.
If, as a printer, you have only known and used multigrade papers then perhaps adopting split grading as your first choice method of printing is perhaps understandable, however for many printers such as myself who learned to print using graded paper it can be perhaps viewed as one more printing technique to be learned and used when required.
The first of the two methods for arriving at the correct exposures needed to make a split grade print involves first making a test strip at G0 or the softest grade of your choice. Use the form of exposure timing you have, either the f-stop method or straight analogue timing to make the test. Process normally and because of the effects of dry down it is ideal to dry this strip completely before trying to make the selection of the right exposure. You can briefly using a micro wave oven to do this, although it is only needed if you are using fibre based paper as with resin coated there is little or no dry down effect to worry about. This test is for the soft exposure, and a choice has to be made that shows detail in the highlights and mid tone areas, you are not looking for contrast at this point, just tonality. This is probably the hardest part of the whole process especially with fibre based paper where highlights will appear invisible when the paper is wet. With experience it does become easier to assess a wet test strip with out the need to dry it. When the exposure has been chosen, make a second test strip at the chosen G0 exposure. Then with the paper strip still in place change the filtration to G5 and make a step test at G5 over the G0 exposure. This is where the G5 filter provides the contrast, and choosing the correct G5 exposure from this combined test strip will always be subjective and open to interpretation. Finally make a full print use the chosen exposures first for the G0 and then the G5 exposures. Assess this print and plan any burning and dodging that may be required.
Dodging and burning
Any decision made regarding dodging and burning using split grading will always be subjective and dependent on how the photographer wants to interpret the negative in the final print. I have found that it is not an intuitive process and can take a while to understand and do well. For example, a sky can be darkened in several ways again depending on the desired result, extra G0 can be shaded in using a piece of card to give a smooth tonal result. Or equal amounts of G0 & G5 would achieve a G 2.5 tonality and a different look. Equally, an area of shadow can be held back during the G0 exposure and printed in with the G5 exposure to give definition to shadow detail. By balancing and adjusting the ratio of the burn exposures between the hard and soft grades with a little experience it is possible to achieve predictable results.
The second method for obtaining the G0 & G5 exposures for split grading is to start by making a test strip at G2.5, half way between G0 & G5. From this test chose an exposure that gives a good overall contrast and tone for the negative. Then divide that time in half and make a second test using both the hard and soft filters giving half to G0 and the other half to G5. For example if your chosen time from the G2.5 test is 16secs, make the second test giving 8secs to G0 and 8secs to G5. Look at this second test and evaluate it for any burning or dodging that may be required.
My own workflow has changed over the years and I have evolved a hybrid form of multigrade printing that I find works for me. Before I go into the darkroom I have already chosen and pre selected negatives to work on and I usually have a idea in my mind of the look I want to achieve in the final image before I start to print. With my workflow I like to establish the contrast that I want in the print first before adding any tonality to a picture. This means I normally start with a test strip at G2.5, unless it is obvious that a negative needs a different grade to start with. From the resulting G2.5 strip I can decide if the grade is correct, if not then I will retest at a different grade, either harder or softer. If I choose an exposure from the G2.5 strip to work with, I can add a higher grade exposure to the image where needed, and maybe bring in the sky with a lower grade, perhaps G1. I will also look to see if there are any highlights areas that will need any additional exposure at a lower grade or a flash exposure. Again it is all depends on how I want the final print to look. Printing this way I know specifically what grade I am putting in a certain area, also by starting with a G2.5 test strip I also have the option to use the second method of split grading as described above, if I feel that would help in producing the print I have in my mind.