Split-grade printing is a technique used to achieve satisfactory prints from difficult negatives, particularly those where dense blacks and subtle lighter tones are required. An example might typically be a landscape having a bold foreground but a weak sky. It might also be used for high key portraits having a predominantly light or white background, but still requiring skin tones to be properly rendered. This process works only with multi-grade papers.
The first stage is to assess whether a print will really benefit from split-grade printing - not all negatives are suitable. A test print is then made on grade 4 or 5 paper. This should produce quite stark results, with the black areas rendered very dark and not much detail in the lighter areas.
When a test print has been assessed, a full print has is made making sure to note development times and settings. A second print should then be exposed but at about three-quarters of the original exposure. The second print should remain in place when this exposure has been completed. The enlarger is then reset for a softer grade, typically around 00. Set the enlarger for an appropriate time and make a test print across the pre-exposed paper.
The test strip is then developed as normal and the results are examined. If dark areas are now too dark then the grade 5 stage can be reduced a little to allow the grade 00 stage to make up the difference. Good highlight definition should be apparent. Load a new sheet of paper, select the grade 5 settings and expose appropriately. Change the grade setting to 0 by dialing in the new settings or changing to the appropriate filter. Expose as appropriate, and develop as normal. Some prints require a degree of dodging, particularly to maintain a white background.