First, What I did.
1. Primed the base grey.
2. Painted in white.
3. Took the same white and darkened it some by adding black.
4. Did this in a lightning design on the base.
5. Mixed black ink and sepia ink and then watered it down.
An important step that I didnt do mainly due to a lack of material is the glossy finish from a sealer of choice. Here is how it turned out.
What I learned is easy enough.
1. I need to use a different white as the base and there needs to be more distinction between the different white use not just a very subtle one.
2. I need to water down the inks even more and maybe only use the sepia one or the black one not both.
3. Without the glossy seal it wont look right.
4. Once I figure this out it is a technique that could easily be done on other piece to create bits of marble for bases or whatever.
I will be trying this again in the future and will also pick up some glossy sealant at some point so they can get a proper view of it. I am also planing on starting with more of a bone white color rather than a pure white next time and darken and lighten it from there for the different veins in the marble.