Overlay

Overlay Tutorial
Turn your ordinary penicl and line art into a digital paints with great ease using the Overlay layer blending.

Open the grayscale art, make sure color mode is set to RGB under Image menu.

Hit ctrl U or go under Image>Adjust>Hue/Saturation and reduce lightness to -50. This will make all of your whites nuetral gray.

Double click the layer to change it from background to layer 0, then change layer blending to Overlay (softlight has the same effect, but is lighter generally than overlay)

create a new layer and position it underneath the art.

Just start with filling in flat colors underneath the original art. Overlay will allow the colors to show through, in a similar fashion to Multiply layer blending, but it also changes the color based on the values on the above artwork. So your black with come out dark green, whites will come out light green, etc. I like to take out all the white and leave it all gray so I have more control over highlights.

The art will look okay at this point with just flat color fills, but go ahead and use the dodge/burn tools to add more dramatic highlights and shadow. This will enhance dramatically.