Museum Black (100% pure pigment) This ink has remarkable longevity and will not produce any visible fade (similar to all of our gray dilutions).

Portfolio Black (92% pigment, 8% metal complex) This ink has about 1/2 to 2/3 stop greater dMax than Museum Black. This ink is for users in which longevity is not as important as density. For use in portfolios this does not present a problem. However, for long term display this black will eventually lose density. Has been know to be affected by some batches of Hahnemuhle Photo Rag (though this has been rare.)