Opacity of multiple layers

Hi, I need to change the opacity of multiple layers at once. I have objects on more than 1 layer (for various reasons) and I want to change the opacity on all of them. Ideally I'd want them all to change as if they were just one layer (as if merged together), so if I set the opacity to say 50%, I see just the background beneath and everything else at 50% (instead of all the layers beneath showing through each other at varying opacities). This image illustrates better what I'm after:

https://dl.dropboxusercontent.com/u/163 ... ity_c2.png

Can anyone think of a good way to achieve this in C2 (is it possible to somehow group the layers together for example), or is my best bet trying to shove everything on the same layer in order to make it work?

You can use System > Set Layer Opacity and change it for one or more layers based on a certain condition

Thanks for the reply. I've come to conclusion it's probably best to just try put all the objects needing opacity change on the same layer to get the desired effect (without them showing through each other if overlapping)..

You could also put all the sprite objects in a Family and change the Opacity for the Family.