Creating depth by using varnish?

[Arydis]

The goal is to make a miniature's shield look almost like a cracked crystal portal (to a galaxy).  My thought to achieve this is to create an illusion of depth with an underpainting, MANY layers of varnish, and even small touches of paint between layers.  Being a mini, there won't be too much bulk, but I wondered if anyone had any experience with a project like this and could offer any pointers.  Would this idea work?   

[Doug's Workshop]

I've done "cracked" marble that looks pretty good, and you won't get there with layers of varnish.

 

The layers we work with are just too thin to create the effect you want.

 

What I do is to get some thinned paint and very very very lightly make the "crack."  Do this a couple times, creating the deepest cracks.  Then, a couple more with slightly darker paint.  Keep all the lines roughly parallel, grouping the faintest in one direction (let's say 45 degrees), then the next 'level' at 55 degrees . . . creating the illusion that there are different levels that crack in slightly different ways.  The effect is that things deeper will not be as visible (you can do the same thing when painting a landscape by keeping the colors lighter - it gives things in the distance a fuzzy feeling of distance).

 

It's also important not to draw straight lines when doing the cracks - nature doesn't like straight lines, so have a lot of coffee and draw your line.  Lightly.  Like, barely touching the surface light.  Use a brush with a very good point.

[Gadgetman!]

If you want layers with any thickness at all, you may want to try out Tamia Clear Arcylic Paint (sku: X-22).

It's NOT a vater-based acrylic, though, so you need to be extra, extra certain that the previous layer is absolutely dry before adding another...

It's also 'not good' for good brushes.

[Arydis]

I wanted to try it out to see. This was my result. Thanks for the tip about the lines Doug!