faint lines...

 From:  Michael Gibson
4896.2 In reply to 4896.1 
Hi niko,

> a result of imperfect tangency or simply the outcome
> of having a second surface created inside another one?

Looks like imperfect tangency.

> If I were to manufacture that part would those lines
> be there?

It really depends on which manufacturing method you were using.

But it's not too likely that such a small subtle detail like that is actually going to come through the manufacturing process.

- Michael