Proposed method to measure ink colors

[Grandad35]

The purpose of this thread is to revive the concept first proposed in (http://www.nifty-stuff.com/forum/viewtopic.php?pid=3164#p3164) but later abandoned because we couldn't generate repeatable samples. Simply stated, the goal is to generate a catalog of CIELab colors for known inks so that we can (hopefully) identify an unknown ink by matching its color to known inks. A secondary goal is to make it possible to select individual colors from the supplier with the closest match to the OEM inks. This should give a closer color match to an OEM inkset for those who don't want to deal with profiles and are willing to run a "mixed supplier" inkset. At the very least, we would have a scientific basis for deciding which ink colors caused a color shift.

Canonfodder and I have been corresponding on this subject for a while now (the initial posts are at http://www.nifty-stuff.com/forum/viewtopic.php?pid=8159#p8159). After a LOT of work, canonfodder has developed a method for applying a known quantity of ink to a known sample size in a very uniform manner. While his method is simple in concept, it requires a great deal of skill in its execution to achieve the desired results. For this reason, canonfodder has volunteered to do all of the sample preparation and I will do the spectro analysis of the samples and post the results. Canonfodder will also post the details of his technique for those who are interested. Note that only a very small amount of ink is needed for a test (about 0.2 CC - about 20 drops), so this amount of ink can easily be obtained from even an "empty" cart or by dripping some ink from the exit of a full cart into a 1/16 ounce vial (which can be supplied by canonfodder, or ordered from www.discountvials.com). Because the ink volume is a critical detail in the test, evaporation of the water from the liquid ink sample must be avoided. A cart which has been empty and unsealed for weeks may not yield a satisfactory ink sample.

We have decided that the first inks to test should include:
1. Canon OEM BCI-6 inks. I have a set of these carts, and will supply all 8 colors (C/M/Y/K/PM/PC/Red/Green).
2. Canon OEM CLI-8 inks. Canonfodder has C/M/Y/K, but we need PM/PC. I can find PM/PC/Red/Green CLI-8 carts on the web, so I assume that they are available. Is there someone who is willing to supply empty OEM CLI-8 carts of these colors or some ink from working carts?
3. Formulabs BCI-6 inks. I have all 8 colors and will supply these inks.
4. Image Specialists BCI-6 inks. I believe that MIS sells these inks. Is there someone who would supply samples of these inks, preferably all 8 colors?
5. Image Specialists CLI-8 inks (MIS). Canonfodder has C/M/Y/K, but we need someone to supply PM/PC/Red/Green.
6. OCP BCI-6 inks. These inks aren't common in the US, but they are common in Europe. Are there any volunteers to supply these inks?

The second round of tests would include popular inks of unknown parentage. This could include Hobbicolors, G&G, and a few other popular prefilled carts. The obvious problem with these tests is that our results will only apply to the single sample that we test. Since the suppliers of these inks are unknown and can be changed at any time (as evidenced by http://www.nifty-stuff.com/forum/viewtopic.php?id=1518), this data may be interesting but it will be far less reliable than the first set of tests.

Both canonfodder and I are running with custom profiles on our 3rd party bulk inks and are quite happy with the colors that we are getting, so this project is only of scientific interest to us. The real value will be to those who want to match OEM ink colors while using 3rd party inks. Is there sufficient interest to justify the work involved?

 

[Tin Ho]

You can't identify a unknown ink by matching its colors to known inks. If a 3rd party ink is so perfect that it matches exactly to the OEM colors will you identify it as OEM ink? I don't mean to pour cold water over the proposal. I doubt the statement's validity. Let's not make false conclusions for 3rd party inks. Don't we all agree that Consumer Report make false conclusions all the time? We indiciduals all make false conclusions, also called opinions, all the time too.

 

[mikling]

I can supply Image Specialists samples for ANY of the specified Canon Colors and I also have ALL the inks for the Canon PRO 9000 as well right now in case anybody was thinking of getting that fantastic printer but was afraid of running costs.

So yes I can supply the PM,PC, Red and Green also the BCI-6 Colors.

Now one word of caution. The generated colours are ideal under an inkset system. Thus the real colors are reached when all inks are used from the same source. Mixing and matching might not be the best thing to do and wrong conclusions can also be had.

Furthermore, beyond the color fidelity to the original, there is the issue of matching the physical properties to the original. That way sponge/ink interfaces are closely matched as the manufacturer had intended. Contact me via email if you wish to proceed with the tests.

Personally this is not a trivial test as Tin Ho states wrong conclusions can be made. I liken this to high end sound systems where the best components all assembled together does not necessarily yield the best balanced sound. Balance is the key, I suspect with colors a similar thing happens because the basic colors all interact to give you a balance of various colors.

 

[ghwellsjr]

Are you interested in testing Inktec inks? I can supply six dye colors and pigment black. I don't have green and red.

 

[canonfodder]

ghwellsjr,

Yes we will be interested in the Inktec inks. I don't know how popular their inks are, but upon examining their website, I see that they are a serious supplier and they claim to make their ink, not just sell it.

mikling,

We will sort out just which inks will be needed from your available ones.

Thank you both for volunteering samples. We will contact you by email detailing arrangements for liquid sample submission.

canonfodder

 

[canonfodder]

MORE ABOUT INK TESTING
Suppliers who make ink, or are committed to known makers of ink are most interesting, as they normally demonstrate the consistency that we need in order to make testing meaningful and worthwhile. The tests consume a lot of time, so we will not wish to test "unknown source" inks.

PRETTY OBVIOUS STATEMENT, BUT I'LL STATE IT ANYWAY.
We all need consistency in the ink we choose to purchase. If you have expended the time and money to profile your printer, inconsistency makes that a waste and the printing a disappointment. If you have not profiled, but have taken the time to learn what adjustments of your printer setup produce results that satisfy you, inconsistency ruins that effort.

GETTING A BIT TECHNICAL NOW.
The tests will yield the individual ink's CIE L*a*b* values for a standardized sample of the ink. (See information about this color space standard at http://en.wikipedia.org/wiki/Lab_color_space .) This set of numerical values which define a color is easily compared to the similar values for another ink which is intended for the same color use in a printer. The magnitude of the difference between the two inks can be judged as to its importance in terms of detectability by the human eye.

Should the ink test results show that two inks have VERY similar L*a*b* values, the inks cannot be declared as "the same ink". However, they can be declared as "very similar", and one could be tried as a substitute for the other. The usefulness of "very similar" inks comes when a known-to-be-consistent low-cost second-source ink shows its close similarity to, and therefore its probable ability to replace, an expensive OEM ink, without the use of profiling or re-profiling to correct for differences.

The primary use for the L*a*b* values yielded by the ink tests is in the monitoring of those values for consistency. Over time, we will be re-testing the inks in an effort to assure consistency, or detect inconsistency. This will be done especially when there is distinct empirical evidence that a change may have occurred in an important ink.

canonfodder

 

[Tin Ho]

I am not convinced by the idea that some 3rd party ink may be inconsistent over time because you will not know when they will switch their source of ink. This may be true in the pre-filled ink cartridges sold by hundreds of small businesses all over the internet. But there are only a handful of names who sell bulk inks. Has anyone actually experience ink inconsistency from any of them who do not disclose their ink source?

My understanding of the non-disclosure issue of some of these ink sellers is purely a business one. It is a marketing issue. Ink manufacturers are supposed to do their own marketing for their names. The cost invloved in marketing a brand name usually is not what a small business or retailer can afford. The manufacturers have to do it. If they do advertise at their expense the cost will be factored into their wholesale price to their distributors. This can be a significant increase in the cost of ink.

So small ink retailers have two choices, one is to sell the ink without the brand name. Or pay higher prices for brand named ink. Choosing the first means lower cost for ink and smaller business. Choosing the 2nd will require to pay royalty for the brand name but get free marketing by the factory and sell more ink.

Will you believe that MIS is the only seller of Image Specialists inks and Alotofthingsbeing the only one for Formulabs ink? I found it hard to believe. I tend to believe that the issue is really a speculation for the benefit of those who sell brand named inks.

I thought this proposal of testing is to test any ink of interest so that we can identify the good ones from the not so good ones. If you exclude those with unknown sources you are doing nothing good for all of us. The testing would only benefit the brand named sellers and manufacturers, not any of us.

 

[mikling]

Again I am going to state that only SETS should be tested. It is of no value to recommend that you mix a color from one vendor with that of another. It's not practical.

I guess I ( www.precisioncolors.com ) am living proof that MIS is NOT the only one selling Image Specialists inks. I go one step further and label all my shipped inks with Image Specialists numbered ink formulations so that users can have exact repeatability.

Now this does bring out one question. Are my inks identical to MIS's. I don't know for sure. Why? MIS does not label their inks with Image Specialists formulas. They have their own. Exactly what formulation they ship is unknown to the user. I don't have exclusive and hidden house numbers. I have had comments that this is foolish on my part as it doesn't give me private branding like MIS and I am disclosing too much. Well, I think smart hobbyists and professionals appreciate the aspect of knowing exactly what formulation they are using and will come to treasure that as they become wiser about inks.

 

[Grandad35]

I am not convinced by the idea that some 3rd party ink may be inconsistent over time because you will not know when they will switch their source of ink. This may be true in the pre-filled ink cartridges sold by hundreds of small businesses all over the internet. But there are only a handful of names who sell bulk inks. Has anyone actually experience ink inconsistency from any of them who do not disclose their ink source?

Read this thread (http://www.nifty-stuff.com/forum/viewtopic.php?id=435) for an instance where a "known" ink supplier (the one that I use) changed the formulation on a single ink color without letting anyone know. I am sure that they did it will all the best intentions, but the results were not favorable. They subsequently eliminated the new formulation and reverted to the original formulation (remember the "New Coke"? fiasco).

Search the forum for a problem where a prefilled cart supplier switched from pigmented to dye based ink in BCI-3BK carts without telling anyone.

I thought this proposal of testing is to test any ink of interest so that we can identify the good ones from the not so good ones. If you exclude those with unknown sources you are doing nothing good for all of us. The testing would only benefit the brand named sellers and manufacturers, not any of us.

These tests will not identify "good" or "bad" inks - the purpose is simply to identify the color produced by each ink. I don't see a large benefit to testing "unknown" inks. If a supplier won't identify the source of their inks, how can anyone be sure that they won't change suppliers or formulations in the future? Look at the differences in the components listed in the MSDS sheets for several Canon OEM inks:
http://www.usa.canon.com/cpr/pdf/MSDS/IC1274_-0101.pdf
http://www.usa.canon.com/cpr/pdf/MSDS/IC1011_0202.pdf
http://www.usa.canon.com/cpr/pdf/MSDS/IC1228_0202.pdf
http://www.usa.canon.com/cpr/pdf/MSDS/IC1229_0202.pdf
http://www.usa.canon.com/cpr/pdf/MSDS/IC1035_0202.pdf
There is a lot of technology involved in formulating the inks for these printers, and it takes a skilled and experienced group of people to undertake such a project.

Again I am going to state that only SETS should be tested. It is of no value to recommend that you mix a color from one vendor with that of another. It's not practical.

We DO plan on testing complete sets of inks, and we will report the individual color values measured for each ink. I agree that it's ideal to print with a matched set of inks, especially if you have custom printer profiles. However, I don't see a problem with printing with a "mixed set" of inks if that gives a better color match to OEM inks for those who do not use profiles.

Actually, I have often wondered why the various ink suppliers don't supply a custom profile for their inkset to get a match to OEM ink colors. At first look, this would seem to require a profile for each printer model and paper combination. However, it should (theoretically, at least) be possible to use the canned Canon profiles supplied with each printer model in series with a few (one each for 4, 6 and 8 color printers) custom profiles to do this by double profiling. Normally, double profiling is a bad thing, but why not use it to your advantage in this case?

 

[Tin Ho]

This has become a little funny. If an ink of a known source did that without notifying customers how can you expect inks from unknown sources not to do that? You won't test ink from vendors who do not disclose their sources because colors may be inconsistent over time. But you will test inks of known sources although colors may be inconsistent too. I can not see a logic here.

A few years ago I purchased a set of refill ink from a now defunct but still exist business only to be completely disappointed to find bacteria growing in the PC ink. I am not going to name the business here but my point is even the ink was tagged with a big brand name it is no more worthful for testing. If you plan to test only known names such as Image Specialists and Formulabs and whatever you can name them the test result would be perceived by me, and probably many others too, that you guys are doing nothing but marketing for these names.
This is what Consumer Report did all the time. What makes your test different?