Okay, so I asked about opacities
but I'm beginning to think my question might be symptomatic of a larger issue. So, lemme ask:
First off, I'm in Photoshop 7.
When I use a color fill layer, either as a real live "fill" layer set on "color" or, more often, just a colored rectangle or a gradient-colored rectangle set on "normal," I put it BELOW the image I'm colorizing, and then tweak the opacity/fill percentages of the image layer to let the color layer show through (or use eraser brushes on the image layer to let the color layer show through selectively).
I seem to be noticing that other folks put the fill layer *above* the image layer, and other folks seem to have more of a handle on the difference between the "opacity" and "fill" faders than I do, and I wonder if these two facts are related.
Have I been doing something wrong, putting the color layer *beneath* the image layer? I've tried putting it above but I'm so used to my usual technique -- and also I don't quite get the physics behind the *above* technique -- that I haven't been able to do anything with it.
Could someone explain a little more to me about the best use of color fill layers, and also the difference between the opacity and fill percentages?