Quote Originally Posted by gainer
One is to print the negative of the step wedge on the printing material in question and note the number of steps between black and white. A print of the original wedge directly on the printing material will show the effective number of steps in the SBR. Dividing that by the number of steps in the print of the negative will give the effective contrast index when those development conditions are used on any scene to be printed on that medium.
Alternative printers have been testing their materials for decades with step wedges. We were using the wedges long before any of us had any idea that there were actually densitometers that could measure the UV stain. Or could afford them!

This method of testing is essential because the range of exposure scale that people get in practice with altternative processes is much greater than the range people get printing different brands of silver papers. The pH of the papers, sensitizing mix, method of coating, and type of developer combine to create a much more variable scenario than silver printers see.

Sandy