Method to measure ink colors

[Grandad35]

The original post has been edited to include a retest of the MIS CLI-8Y, as well as OEM BCI-6PM, OEM BCI-6PC, Formulabs BCI-6 PM and Formulabs BCI-6 PC.

Our initial test of the MIS CLI-8Y (CLI-8Y_MIS_Orig on the spreadsheet) looked strange at the longer wavelengths, so a retest was run (CLI-8Y_MIS on the spreadsheet), and the retest data is included in this analysis. Canonfodder is very meticulous in his ink application procedures, so we are fairly certain that the problem wasnt in contamination during the application of the ink, but rather that the Orig ink sample was pulled out of a 2 oz. bottle that was almost completely empty. It is possible that there was some foreign material in the dregs that affected the color of that sample. The retest sample was drawn from a nearly full refilled cart. Obviously, we will be very careful about how the samples are obtained for future tests.

See the original post for the discussion on the PM and PC inks.

 

[fotofreek]

The issue you mention is interesting. Colors may shift when a nearly empty container of ink has permitted either enough evaporation or oxidation to occur.

 

[Smile]

Any information on method to apply solid ink on ink patches method? Is it ready yet?

 

[mikling]

Fotofreek I once mentioned this issue concerning buying large containers of ink. The relative volume of air relative to the remaining ink is large as it is emptied. This will cause high levels of evaporation and the ink properties shift. At the extreme you get print quality problems. So there's another issue with acquiring larger volumes other than aging.

The best thing to do if one buys large containers is to transfer a small amount to a smaller container and use the ink from there. One should only open large containers as infrequently as possible and transfer remaining amounts to a smaller container where the relative volume of air to ink is small.

It's good practice but many don't do it and everything is fine. So it depends on how fastidious one wants to get.

 

[Grandad35]

Mikling,

I agree with your advice - transferring ink to (and refilling from) small squeeze bottles is a good way to do this.

It should be noted that the dE between the questionable ink and the retest was only (3.7). The change in their spectra shows how sensitive this test is, but it is highly unlikely that any human could see such a small difference in just one of the inks on a photo print, given all of the other things that cause changes in the color between the monitor and the printer.

 

[Grandad35]

Red and Green OEM and Formulabs inks were added to the original post. The spectra of the red and green are interesting, in that they "fill in some of the holes" between the C/M/Y inks.

 

[Grandad35]

Any information on method to apply solid ink on ink patches method? Is it ready yet?

Canonfodder has put the testing of ink samples ahead of writing up the procedure but he will start on the documentation fairly soon.

 

[Smile]

Any information on method to apply solid ink on ink patches method? Is it ready yet?

Canonfodder has put the testing of ink samples ahead of writing up the procedure but he will start on the documentation fairly soon.

Thanks for your reply, please post on this thread when it is ready

 

[Grandad35]

Red, Green, PM and PC BCI-6 inks from IS were added to the original post and spreadsheet.

 

[Grandad35]

Formulabs CLI-8 Cyan, Photo Cyan, Magenta, Photo Magenta and Yellow were added to the original post and spreadsheet.