Something that has not been previously mention on this site is how much my personal work incorporates hand coated platinum/palladium prints with my digital workflow, and how digital photography and inkjet printing has allowed historic alternative processes to gain more widespread use. This is not news at all, and many people have spent the last 20 years developing techniques for making digital negatives for alternative process.
Dedicated Print Drivers for Digital Negatives
QuadToneRIP is the best option for for making digital negatives with the standard Epson inks (as well as dedicated monochrome ink sets, but which require a much different approach). But, there are two downsides to the way QTR negatives have been traditionally created. The first drawback is the time-consuming calibration process, which involves entering settings for the ink levels, partitioning information, and the correction curve and linearization information into a text file. The settings in the text file are then compiled by the QTR curve creation program to generate the ink values the QTR driver uses for printing. This workflow is not overly complicated, but is not without its own learning curve, and is often the source of frustration for people making digital negatives with these systems. To do well, there is a minimum of four printing steps, along with measurements, manual calculations, optional Photoshop plugins or spreadsheet tools used in the linearization process, all of which can take several hours to several days to arrive at a good negative.
The second downside is the shape of the ink curves themselves (the shape referring to the graph of the ink levels for each ink channel). The QTR curve creation program will always result in sharp changes where the ink levels ramp up, overlap, and drop off. Additionally, the traditional QTR curve does not allow for long, tapered ink ramps and do not overlap as much as needed for making smooth gradients. The sharper ramps can cause problems in the linearization steps and can result in banding where one ink ends and the next begins.
A Whole New Approach to QTR Digital Negatives
My new QuadToneProfiler-QuickCurve digital negative system takes a whole new approach and removes the QuadToneRIP curve creation workflow altogether. The new system uses a specially designed set of quad curves for finding the needed blocking density for your process, and a simple method for setting that blocking density in the custom-designed starter curves.
The starter curves with the required blocking density are installed and used to print 21-step negative.
That negative is then printed with your standardized process, and the density measurements from that print are entered into the QuickCurve-DN workbook.
The next step is where the new system really shines. Once the measurements are entered into the profiler, the final quad curves are automatically corrected to the required ink levels using my own system of smoothing, interpolation, and linearization formulas.
You will never need to use the QTR tools for these steps again, and it means that re-profiling for different papers or processes can be done with very little effort, without compromising the quality of the final print.
How well does it work?
One of the best comments I've received from the first few customers came from long-time platinum/palladium and photogravure printmaker, Keith Taylor. He said, "It’s really the smartest, easiest and reliable method I’ve found so far!"