I used the same method here, as I used on the coloured pens I posted recently. Only difference being no finish was applied.
Dark Olive before and after.
As you can see, all that has happened is the wood took on a general colour with no penetration.
The same occurred on a more figured piece of Olive.
Then I tried a piece of Silver Birch with some figuring in.
Despite the figure in the Olive, it is tight, and actually long grain.
The Birch however, is from near a burr. Most of the bits which take up the colour are actually end grain, to one degree or another.
I also tried, (but didn't picture) rubbing the stain into a long grain flat piece of Plane.
Guess what?
It just coloured the wood and didn't highlight the grain.
It does pick up in more open grained timbers as I've done it before using the stain neat, on Ash, and Elm bowls, but I think if you want a variation in depth of colour, it has to be burr. Cross grain might show some interesting results, also.
Dark Olive before and after.
As you can see, all that has happened is the wood took on a general colour with no penetration.
The same occurred on a more figured piece of Olive.
Then I tried a piece of Silver Birch with some figuring in.
Despite the figure in the Olive, it is tight, and actually long grain.
The Birch however, is from near a burr. Most of the bits which take up the colour are actually end grain, to one degree or another.
I also tried, (but didn't picture) rubbing the stain into a long grain flat piece of Plane.
Guess what?
It just coloured the wood and didn't highlight the grain.
It does pick up in more open grained timbers as I've done it before using the stain neat, on Ash, and Elm bowls, but I think if you want a variation in depth of colour, it has to be burr. Cross grain might show some interesting results, also.