I am speaking of two possible ways, both using polymer plates which have the potential of raised surface or recessed surface.

one method which I have done is the raised surface where each colour and black is rolled on to the raised surface, the ink is mixed just before printing and plate is prepared then with pressure each layer is put down..

second method which I have not done YET is the recessed surface where the ink goes into the recess and the top is wiped off then with pressure the ink is transferred to the paper.

In both cases the ink I am referring to is of the most light fast available.

The pigment load in my laymans mind is very high, then I think of the inkjet prints that I also do by shooting ink through a nozzel, and from my understanding the pigment load is much smaller to get through the nozzels..

Therefore my question which one has the possibility to last longer?

Second question as I have no history learned of the intaglio or photo gravure process , when did this process start using colours? and how long do these prints last?
There must be some here amongst us who have a background of ink printing and may have some answers.

I am most interested in four colour and I thank Mustafa for bringing this thread.