Oil on Skin

Drops of oil or just the appearance of a nice, smooth gistening coat of oil?

Smooth glistening coat of oil

Tony,

Didn’t want you to think that I had abandoned you…

I was actually hoping you’d say drops, as that’s pretty easy to do. But, I love a good challenge, and in what little spare time I had, I came up with this.

Base image was an 8½ x 11, 300ppi RGB image.

Step 1: Duplicate the image 2X. Name the topmost duplicated layer ‘Top’ and the bottom ‘Copy.’ Step 2: Desaturate the Top layer (Ctrl + Shift + U).
Step 3: With the Top layer still active, go to Image>Adjust>Brightness/Contrast and set the contrast to +50
Step 4: Go to Filter>Render>Lighting Effects. Choose a Directional setting, and crank up your shiny and metallic sliders. Apply the filter to the Top layer.
Step 5: Set layer blend mode of the Top layer to ‘Difference.’ Step 6: Merge the Top and Copy layers (name the resulting layer ‘Modified’). This should leave you with 2 total layers. Your original image, and the modified image layer.
Step 7: Desaturate the Modified layer.
Step 8: With the Modified layer active, open your Curved dialog. Select the white eyedropper and select a light gray portion of the image. This will set your white point and increase the contrast of your Modified layer.
Step 9: Set the Modified layer blend mode to Luminosity. Step 10: On the Modified layer, open up your Blending Options menu. Hold down the Alt button and select the right triangle of the black slider under "This Layer." Drag it to the right until the reading reaches 207 (this setting may vary from image to image depending on your taste).

That’s it. With grayscale images the effect really works well as a whole. With color images, the oily effect shines (pardon the pun) with high contrast images (high ratios of shadows and highlights; it does tent to "gray out" more neutral flesh tones—this can be easily remedied by some careful layermasking on the Modified layer.

Hope this helps. Perhaps someone else will chime in with other solutions/better options.