I have a nested comp that's too small--you can see the edges of the comps instead of the wisps flowing fully offscreen. (See picture.)
I tried to make the nested comps bigger, but then everything was scaled up--much like "image size" in photoshop--and what I'm looking for is more like canvas size, to make the comp bigger but keep all the elements the same size.
PS: got a nice smoke writing effect using scatterize, blur and mesh warp
Emily, don't scale the precomp, scale the layer(s) inside the precomp. Double click your precomp to gain access to the comp containing the layer(s) that make it up. Then scale it/them. I'm sure you probably know not to go past 100%. If you want you can lock the window for your primary comp first, so that you can see your results as you scale, or set up a two-window view.
If the layers in your precomp were all vector based imagery, you could scale the precomp with the Continuously Rasterize box ticked.