Users of this new line of printers have been raising questions about the role and volume of CO (Chroma Optimizer) consumption, having observed that CO cartridges need more frequent replacement than other inks used in this printer, relatively more CO seems to be used for smaller sheets than larger ones and CO is also being used for matte paper, contrary to other information that it only coats gloss/luster paper. I too have noticed this and decided to have a look at CO consumption over a range of print jobs. The purpose is to determine how much CO is being used relative to the other inks, and whether the amounts used correlate with different job characteristics. Before I get into it – firstly big kudos to Canon for even putting software like an Accounting Manager into a desktop printer. It provides welcome transparency into information about product usage characteristics and costs that many people need or like to have.
The database consists of 98 jobs that I did over January/February to about end March 2017. The photos in these jobs were not selected and printed with the purpose of scientifically isolating variables particularly relevant to CO consumption. I left the CO mode in its default “Auto” setting, rather than full sheet coverage. The scope of this note is about volumes (not costs). Canon issued a firmware update in February 2017, which I implemented on February 21st before printing on that day.
All of the data used in this note comes from Canon’s “Accounting Manager” utility, with some rearrangement to facilitate analysis. It accounts for the ink lay down on paper and for total CO usage. In this utility, SQFT (square feet) of paper is the total sheet size, not the inked coverage of the sheet. This means that varying areas of un-inked surface from one job to the next could affect some comparisons. Jobs 1-60 cover January/February 2017 and Jobs 61 to 98 cover March 2017.
There are three main variables of interest to CO usage in this data set: kind of paper, size of paper and whether before or after the firmware update which I implemented February 21st.
I’ve divided the data into seven clusters (a to g), explained as follows:
(a) various kinds of letter-size or A4 size matte papers before the firmware update;
(b) an A3+ and A4 matte sheet for items 25 and 26 respectively, after the firmware update;
(c) A3+ luster paper before the firmware upgrade, except for 35 and 36 which are letter and A3+ luster paper before the firmware update;
(d) A3+ luster paper after the firmware update, except for 38 which is letter size luster paper after the firmware update;
(e) letter size or A4 Pro Platinum (luster) paper before the firmware update;
(f) letter size Pro Platinum after the firmware update, except job 58 which is plain paper;
(g) 17×22 inch matte before the firmware update.
Examining the seven categories in Figure 1, the general summary observations on this data set are that CO as a percentage of total ink use is on the whole considerably less after the firmware update than before, less for larger sheets than for smaller sheets and less for matte than for luster, but still present.
My samples here consumed a total of just about 70 SQFT of paper. In aggregate, that 70 SQFT used just over 95 ML of CO, i.e. more than 1 ML CO per SQFT of paper. That goes a long way to explaining why the CO cartridge expired so quickly.
These observations are again confirmed looking at CO ML/SQFT for the January-February series (Figure 2).
Figure 3 is another representation of the data, this time showing Total Inks ML/, as evident from Figure 2 – heavily influenced by CO usage.
As we’ll see below, the firmware update lowered the total CO usage for all the jobs but the two remaining issues are why the CO share should vary inversely with paper size, and why there should be any CO usage for matte media.
I put these questions to Canon and received a rather straightforward explanation that clears up these mysteries quite fully. It turns out that for the Pro-1000 model only, because users cannot wipe the platen manually as possible for the other Pro series models, CO is also used for automatic maintenance of the platen after every print regardless of whether the paper being put through the printer is luster/gloss or matte, but the amounts used for maintenance are not proportionate to the size of sheets being printed – i.e. the maintenance volume varies less than proportionately to the size of the sheet being printed, hence the ratio of CO to total ink will be larger on smaller sheets than on larger ones.
Turning to the March results (Figure 4), all after the firmware update, we have a very different picture.
Everything from Job 61 to 89 inclusive was A3+ luster. CO as a percent of total ink generally remains a fairly uniform ratio in the range of about 19-20%. Jobs 90 to 98 in Cyan bars are for letter size paper, the filled bars being for luster paper and the patterned bars for plain paper legal size. The same kind of relationships as described above maintain, but at much lower overall levels given the firmware update. Figures 5 and 6 confirm Figure 4.