Eh... uhm...and there I thought it was a Red Bull can on a train track...
...but as tube it actually looks pretty cool!
There's a bit of a logical problem with the merging as of now, if you work with different bump heights or different looks per layer, because they are only different per layer. A single layer only has one look right now.
I have created a different test app that also has shading properties in the material itself, so you can mix glossy and dull paints and so on, but I don't have it in Verve, yet.
With the bump-height it is another little logical issue, because the material amount also determines the opacity- or amount- of color. Thus, I can't just reduce the amount of material you merge down to meet the bump height setting you have set differently on another layer. My advice is just to keep the layers, where's the harm! Only merge where you know you can, but it takes a moment to digest that information and experiment with it.
What I often do is: I make a sketch in the original layer. If I like it I add another layer beneath and fill it with a background color ( [ctrl]+[shift]+[f] ). Then I merge the original layer down onto it, for example. I often do additive layers where I add some brightness gently and then merge that back down.
Eventually I will revisit all of this some more and make it less confusing, I promise!
Jim's tip to save often is a good one! Take it to heart!
Posted: Thu Jun 05, 2014 9:37 am
.... but I love Verve so so much 
The layer merge is an "experimental feature" still ... 
... Actually, appears to me like a soft and cosy satin blanket 