Method to measure ink colors

[Grandad35]

Pharmacist,

We have now completed testing almost all of inks that Canonfodder and I initially planned on testing. Running these tests is time consuming, so we only plan on testing additional ink sets if there is more than just a passing interest in getting the data.

We are concerned that we don't know (and can't find out) who makes other inks, and that the inks shipped under the same name could change at any time in the future. Having said that, we are willing to test a limited number of these ink sets if there is enough interest. Almost by definition, this means that an end user will be willing to provide samples. This also helps to ensure that the samples that we get are typical of the ink that is being shipped and is not a specially selected set.

 

[Grandad35]

The OEM BCI-6G was retested, and the 2 samples fell within a dE of 3.2. The data for the first test was used for the plots (both sets of data were included for reference in case you want to compare them).

The Formulabs BCI-6G was also retested (because the first comparison with the OEM BCI-6G looked strange). The retest matched the OEM ink more closely, and was used in the comparison. I dont know for sure what happened with the first test, but it appeared to be much stronger than the retest. Perhaps I didnt shake the bulk ink container before pulling the first sample and got a concentrated sample?

A 17% diluted sample of OEM BCI-6C was tested and compared to OEM BCI-6PC it gave a very good match (dE=4.8).

A 17% diluted sample of OEM BCI-6M was tested and compared to OEM BCI-6PM it gave a reasonable match (dE=9.0), but not as good as the PC.

This confirms that the Photo inks are just diluted versions of their full strength cousins, and explains why these inks have such a high usage.

Running these tests has been very educational and interesting for Canonfodder and I, and we have now generated all of the information that we wanted. Since there have not been any offers or requests to supply additional ink samples, this completes our testing.

 

[ghwellsjr]

A 17% diluted sample of OEM BCI-6C was tested and compared to OEM BCI-6PC it gave a very good match (dE=4.8).

A 17% diluted sample of OEM BCI-6M was tested and compared to OEM BCI-6PM it gave a reasonable match (dE=9.0), but not as good as the PC.

This confirms that the Photo inks are just diluted versions of their full strength cousins, and explains why these inks have such a high usage.

I'm wondering if you are planning to make your own PM and CM: 1 part ink, 5 parts water? Sure could save a lot of money.

 

[Grandad35]

I'm wondering if you are planning to make your own PM and CM: 1 part ink, 5 parts water? Sure could save a lot of money.

Canonfodder and I have already discussed this, but there is far more to formulating an ink than just the color. In decreasing order of importance, I see (at least) these additional needs:
Surface tension
Humectants
Mordants
Anti-kogation agents
Viscosity
Nucleating agents (maybe)
Antibacterial agents
Many other things that we dont even know about.
I'm afraid that PM and PC made by just diluting M and C with distilled water wouldnt work well, and could destroy the print head. I have some cleaning solution which is said to be the base used for inks, but it cost almost as much as the ink itself. By refilling with bulk ink, my costs are already so low that the potential savings arent worth the risk. If these inks were needed in commercial quantities, it might be worth the effort to design a workable formulation, but it wouldn't be a trivial exercise.

BTW PC needs a 5:1 dilution, but PM needs a 9:1 dilution (at least for Conon's BCI-6 inks)