Almost all focus on profiling printers has been the number of patches and size of patches. This turns out to be wrong in that most of the error associated with Pro1000 profiles has little to do with these. On the Pro1000, they are secondary or even tertiary factors.
Over a year ago I noticed that the Pro1000 had a "warm up" problem and that if I printed 2 identical pages consecutively the second page had a pretty large color shift. So I got in the habit of always printing profile chart pages consecutively with a "throw-away" page at the start. This significantly improved profile color accuracy.
Then in January, I ran across another Pro1000 issue, color shifts based on the location on the printed page. See this:
https://forum.luminous-landscape.com/index.php?topic=137534.0MfAlab pointed out that the Pro1000 (and some others) suggest limiting printing using an approx. 2" top and bottom margin for the most accurate colors.
https://forum.luminous-landscape.com/index.php?topic=137534.msg1206689#msg1206689So to quantify how much of a factor this was, I ran three experiments using exactly the same set of 957 RGB patches which were from XRite's single page i1iSis chart called: "default-i1iSis."
Three profiles were made from the same 957 patches but the charts were printed differently. Then a set of 91 neutral patches from L*=3 to 93 and a set of 180 color patches randomly distributed in the printer's gamut were evaluated for each of the three profiles. The result was average dE 2000 for the 91 neutral patches and the 180 color patches for each set.
The differences in dE 2000 from profiles made with exactly the same patches were shocking.
Initial, one page 957 patch set: Colors: dE:1.184, Neutrals: dE:0.979
Second, one page 957 patch set: Colors: dE:0.661, Neutrals: dE:0.600
Two pages split with the 957 patch set and 2.5" top/bottom margins: Colors:0.450, Neutrals: 0:507
These changes are so significant that improvements by increasing patch counts are more than offset by errors printing patches using the full paper length. So much so that printing a patch set with a simple 6x6x6 grid and an extra 102 near neutrals for a total of 318 patches, using the optimal process with large, top/bottom margins has better performance than the 957 patches on a full page :
Colors dE:0.652, Neutrals dE:0.397
Here's the exact process for making the 3 profiles each from the same 957 RGB patches.
1. Print the single page, 957 patch image twice without printing anything previously within the last hour except a verified nozzle check. This has 33 rows of 29, 6mm x 6mm patches.
2. Before the print queue finishes, print the 957 patch set divided up into 2 pages with 2.5" margin or more on the top and bottom of the US Letter page.
Then print and measure
* Important Note: This is specific to the Pro1000 and possibly other printers that mention increased top/bottom margin for best color. My Epson 9800 does not exhibit this effect.