The following charts show the percentage distribution of deltaE's for a Canon Pro1000 with glossy using Ethan's list of regular grids with maximum near neutrals from 581 to 2945 patches. See this:
https://forum.luminous-landscape.com/index.php?topic=118987The distributions were created using all, in gamut, integer L*a*b* values, and a subset where a* and b* were within +/- 2 of zero (aka: Near Neutrals).
The Argyll profiling software was used with the following approach. An 8.2k patch set with a 20x20x20 grid and 40x3x3 sub grid along the device RGB neutral axis to create and print 9, 957 patch charts on the Pro1000. These were then read by an i1iSis 2 XL and the RGB/LAB values were processed to create a reference ICC profile.
This reference profile was then used to create RGB/LAB value pairs using the RGB values from the I1Profiler's "smart patch generator" at the counts that produce maximum near neutral extra patches.
Also included for comparison is the XRite 1 page default iSis 957 patch set as well as the "packed" 1 page set I designed that also is 957 patches.
There are two charts. One using deltaE2000 and one using deltaE1976.
Solid lines are, in increasing Patch size (and accuracy) 581, 815, 1105, 1457, 1877, 2371, 2945. These form 7, sold lines on the two charts.
Dashed lines are both 957 patches:
Red: I1Profiler's Default iSis which has 900 patches for the main grid and 57 near neutrals.
Black: My "Packed" set with 855 main grid and 102 near neutrals.
The distribution charts show the deltaE v percent of L*a*b* printed values that are lower. Thje left side is for the full, printable gamut. The right side is the near neutrals (a* and b* are between -2 and 2).
DeltaE 2000:
DeltaE 1976