I've changed my recommendations regarding this toner.
In January I first posted the progress of this blue toner project that is aimed at finding the easiest and most lightfast way to make a truly neutral print from a predominantly carbon inkset. At the time I noted:
...Where 2 pigments are needed to get to the right tone, the narrower the hue angle between them, the better. This should minimize the color drift along the Lab A axis. It turns out the Epson C has a very favorable color.
...So, the two pigments in the toner I'm now testing are Epson Cyan and Lucia Blue,
.... The color pigments are diluted 1:9 with generic base c6c....Mixing Epson and Canon pigments was and is a question I'm looking at. So far no incompatibilities have been found. I've given both this toner and one made with only Canon Lucia C and B a centrifuge test. Both did exceptionally well.
...
In follow-up testing, including centrifuge testing, of the various toner options, the Canon-Epson toner initially used, after being diluted for 4 months, did not do well. There is evidence of a problem with the Epson Cyan. In both a very dilute mix with just the generic base and in the toner blend that included both the Canon and Epson pigments, there are signs of some kind of incompatibility that is causing the dispersion to fail.
While the problem appears even where only Epson C is diluted with the generic base, the problem is notably worse where the Epson and Canon pigments are both in the diluted base -- that is, in the final toner (version 1).
The Canon pigment only versions of the toner and test dilute inks are still looking as good as they did originally. I am seeing no evidence of any problems with the Canon pigments in the generic base. The problem appears to be clearly associated with the Epson Cyan.
Thus, I'm switching to version 2 of the toner. It is as follows:
4.5% Canon Lucia EX Cyan,
5.5% Canon Lucai EX Blue,
90% generic dilution base.
This avoid having two different pigment families in the same blend, and it also avoids whatever problem seems to be causing the Epson C to have trouble with the generic base, at least as a 1:9 dilution ratio.
The color of the version 2 toner is the same as version 1. It is very slightly less dense because the Canon C is slightly less dense than the Epson C. I expect the profiles for version 1 will work the same with version 2.
The hue angle between the two pigments is not quite as good as with the Epson C (which is, of course, why I used the Epson C in version 1). The Jpeg of the color wheel with both of the cyans shows is at http://www.paulroark.com/BW-Info/LAB-color-wheel-2.jpg
The hue angle is now 50 degrees instead of 40 degrees for version 1.
I will get version 2 of the toner in a fade test ASAP.
I recommend people pull toner version one from their printers.
Paul