I've been working to reduce/eliminate subtle color and especially hue shifts that I sometimes see on prints. Especially on the 9800 which has some interesting traits. Unlike my Canon 9500 II, it is very, very good at printing colors that change little. Even after days of no use. But it has some adverse traits as well. The color it prints varies somewhat with the position of that color on a page. And it has some unpleasant, moderately abrupt changes in color when printing neutrals and near neutrals. This largely applies to a* and b* rather than L* and seems to be a shift in colored ink mixing that occurs with small changes in L*. OTOH, the 9500 prints much less consistent colors with shifts of up to 2 dE2k as the ink depletes but also from a day or two of non-use. It also has an interesting history effect. The color of a printed patch depends on the colors of patches printed on the same row. So perhaps there is some temperature shift occurring or other effects altering the colors. But it is a marked affect most noticeable in dark colors. A dark patch that is surrounded by other similar patches tends to be printed slightly more darkly. I do not see this with the 9800. However, the 9500 prints a much smoother full neutral gradient with less rapid variation on each of the 3 Lab axes, L*, a* and b*. So it doesn't benefit as much from a larger patch count or higher resolution profile LUTs than does the 9800.
Lest I complain too much, these are fairly subtle effects. Overall, prints made that are in gamut with both printers look identical outside of slight specular differences from bronzing and reflectivity and those don't occur at all with matte paper.
So, specifically to get the best neutral tone curves for B&W or color printing with a lot of near neutrals, I made a profile target that fully populated the neutrals and near neutrals while including an additional 1914 patches from the I1Profiler Optimize process. The fully populated neutrals and near neutrals were picked so that every A2B1, 3D LUT grid point in I1Profiler's max quality profiles had an associated RGB triplet and measured color. The result was a 4 page iSis target set with just under 3,828 patches
This produced excellent results. Both in more saturated colors and along the neutral axis. Ave dE2k along the neutral axis was under .4 and under .5 for the regular dE76 with maxes under 1.
After seeing those good results I created an expanded near neutral set fully populating not only adjacent neutral grid points but all grid points within 3 locations along each of the three axes.
To this I added a set of RGB values covering all the rest of the RGB values such that every third 3D LUT grid point had an associated RGB triplet. While this doesn't provide as fine a set of colors for those off neutral and near neutral, they are aligned with the I1Profiler's technology when using max quality profile generation. And they should minimize interpolation errors when going from A2B1 which is used for soft proofing.
The result is a set of 2871 patches which creates 3 pages of standard iSis letter size targets. These can also be used for non-iSis charts by importing the CGATs file (Randomized I1P 12x cube etc.txt) and turning them into convenient charts in the desired physical format.
I have included a zip file with two sets, regular, and randomized. I mostly prefer to make profiles from the randomized charts. Especially with the 9500. Some prefer the regularity of standard charts because it can be easier to spot gross defects.
There are a few additional features in these charts. They are designed to be read upside down by an iSis and have the necessary reference bars on both the top and bottom. Rather than read the same chart in the same way twice, I read them in reverse order and backwards then combine the results with a utility that averages the results. I get small improvements doing this. If you wish to read them in reverse order and backwards load the second CGATs file to make the iSis targets.
For those with an iSis, use the ready made targets suffixed ".txf"
Randomized I1P 12x cube etc.txt -> CGATs for Standard Isis Target
Randomized I1P 12x cube etcr.txt -> CGATs for Reverse Order, Backwards Read Isis Target
One note. You can't automatically average the fwd/rev files when creating a profile like you can selecting multiple measurement files and dragging them in. They require the entries to be in the same order. They can be re-ordered if you are handy with Excel or conversant with PatchTool. I use a custom Matlab function to automate this.