Quote Originally Posted by mrcallow
Actually, this is wrong.
1. The rip has no effect on metamerism. The rip simply translate one language (tif, jpg, eps, etc.) into the printers page description language.
2. The couplers in the paper do effect the quality of the print, but will not remove metamerism. The couplers in the paper reduce dot gain, help to increase colour fastness and reduce drying time.
3. The pigments (the things that reflect the colour you see) used in the inks (especially blacks) that give the colours their resistance to fading have this 'special' reflective quality.
"1.The rip has no effect on metamerism. The rip simply translate one language (tif, jpg, eps, etc.) into the printers page description language."

Metamerism is a perceived color change when the print is viewed under different light sources. Gloss differential (sometimes called "bronzing") will not be affected by a RIP because it has to do with printing pigment inks on a gloss paper surface. A clear varnish overcoat is the only solution to gloss differential.

A RIP will affect metamerism. The RIP does not use the manufacturer's printer driver, but controls the inkjet head directly giving much more sophisticated ink control.

Metamerism is mostly associated with the yellow and magenta inks - NOT the black ink. The RIP provides far better ink control - way more control than any Epson driver even with custom paper profiles.

The best example of the ink control difference, is printing a B&W image with a RIP using the full color inkset. You can print a totally neutral, metamerism-free black and white photo using the entire color inkset. You can't even come close to a neutral B&W print with the Epson driver - never mind the metamerism problem.

Basically, Epson printer drivers aren't the best, and don't use the full capabilities of ink or the inkjet head. With a good RIP and Ultrachrome inks, you can reduce metamerism on a color print to the point where it is no worse than a standard wet darkroom color print viewed under different light sources.

Metamersim is a problem associated with all color pigments and dyes, and can affect color perception of any item (car, clothing, carpet, etc.) viewed under different light sources.

Ilfochromes also have metamerism problems associated with the dyes used in the print. When I print Ilfochromes, I do a "best color" color balancing routine using a daylight fluorescent source, warm white source, and tungsten source. When I can get the print to look acceptable (little color change) under all three sources then I know I have the best color balance for the print.