Painting Scale Models - Pre-shadingReal aircraft experience wear and tear in the field. It's common for the panels to have uneven wear, with the center of the panels appearing lighter than the edges.
To simulate this effect on scale models, we use a technique called pre-shading. This is done by darkening the panel lines on the model, then over-spraying with the base color.
Below left, this model has been pre-shaded. Black acrylic paint thinned 50:50 was sprayed through an airbrush at 15 psi. The visible panel lines were sprayed with one or two passes of the airbrush. The lines don't have to be straight, as real wear is uneven. Do the same for the bottom of the airplane. If this looks intimidating, it's really not that hard; visit our airbrush tutorial and get some practice making lines on scrap material.
In the photo below right, the base color (medium sea gray) has been sprayed over the pre-shading. Note that the pre-shade lines are still slightly visible, you don't want to cover them completely. The subsequent camouflage color and dull coats with reduce the effect even more. The final effect will be subtle and just right.
This technique can be used on any model (RC or otherwise) with visible panel lines.