Metamerism

[Tyler Boley]

I'd say it has more to do with the fact that the image forming material (silver, toned or not) is the actual desired hue. With a color printer, the desired hue is "built" from a blend of highly saturated color ink dots, very susceptible to the phenomenon.
Another reason Bruce's comments about the monochromatic ink sets is true.
You did not say which Epson inks, even the difference between UC and UCK3, and what driver was used, RGB, ABW, QTR, or another RIP will make a big difference.
Tyler

[John O'Connell]

Metamerism in silver prints is probably acceptable because ALL the tonalities change at the same rate, when instead an inkjet print is affected mainly in the midtones.
Am I wrong in my perception?

You are correct that a metal silver image does not display metamerism that the eye senses as unattractive because the color is all created by the same chemical.

When you say that an ikjet print is affected mainly in the midtones, you are correct, but the effect is related to both color and saturation. The eye is vastly more sensitive to changes of shade in light to medium tones of neutral shades (tans & greys) than other shades.

What you did---creating a sepia toned monochrome print on an inkjet printer---created almost the toughest test of metamerism out there for that poor printer. Only a headshot against a gray background would have been tougher.

[JPlomley]

I get considerably less metamerism on Hahnemuhle Fine Art Pearl than I do on Epson Premium Lustre, both of which I profile myself from an Epson 7800. If you can live with the saturation at 1440 dpi, this can, in some instances, help reduce metamerism since you are simply depositing less ink on the substrate.