Is there a way to tell a layer with some transparent parts that you only want it to be transparent to a specific layer--let's say the bottom most layer--and not all the layers in between?
I have 20 or so images with transparent parts that move in a fanning out motion. I don't want to see pieces of each image as they move behind those transparent parts, but rather straight to the background layer. Any thoughts?
i think i understand what your after... you want the fanned layers as a group to be transparent, not the individual layers to be transparent.
if that's the case, you can select the fanning layers in the comp and choose layer>pre-compose. in the window that follows, choose to 'move all attributes'. this will move all those layers into a new comp.
in the new comp set the transparency of the layer to 100%. then in the original comp, set the transparency for the new pre-comp to the desired transparency.
if that's not what you're after, if you want each individual layer to blend with the back ground but not with each other, then it's possible, but i'd need to know more about the background that they are blending with... if it's a solid color, or video, or something else. also, if the scale values are different from the fanning layers and the background, that can complicat things too.