Saturation painting requires a special layer to work. In this case it’s an empty pixel containing layer with the blending mode changed from Normal to Saturation. To make it, use the menu command Layer >New Layer. When the dialog box opens, use the drop-down menu to change the blending mode to Saturation and name this layer “Saturation painting.” It’s usually best to put this new layer at the top of the layer stack, so if it’s not there, drag and drop it to the top.
For saturation painting, only two colors are needed—a very saturated color—red, for example—and a totally unsaturated color—gray. Painting a saturated color on this layer, like 100% red (RGB=255,0,0), will increase the saturation of the color under the paint. Painting an unsaturated color, like gray (RGB=128,128,128), will decrease the saturation. The colors themselves, red and gray, will not show up in the image since the layer’s Saturation blending mode insures that only these colors’ saturation affects the original colors in the image underneath the layer. While any color can be painted on this layer, sticking with one saturated color and one unsaturated colors helps to keep things simple.
Incorporating the Masks
Painting through a Saturation mask selection insures that pixels with the most saturated colors receive paint. Painting through a Vibrance mask selection directs the paint to less saturated colors. So by first loading the appropriate mask as a selection and then painting through it with the appropriate color paint, accidentally changing the color saturation of any area, or even any pixel, is significantly reduced. The mask selection makes sure that the correct pixels get paint and prevents other pixels from being painted. And, because the Saturation and Vibrance masks are created using the saturation values of the pixels themselves, most pixels are only partially selected depending on their degree of saturation. This ability to partially select pixels makes sure that the paint strokes on the saturation-painting layer blend naturally with the surrounding areas.
There are generally just two desired outcomes with saturation painting—increased or decreased saturation. The following table describes them and the paint and mask to use for the best outcomes with saturation painting.
|Desired effect||Mask to paint through||Color of paint|
|Decrease saturation of over-saturated colors||Saturation mask||Gray|
|Increase saturation of under-saturated colors||Vibrance mask||Red|
The steps for saturation painting are as follows:
- Create the Saturation and Vibrance Masks on the Channels palette/panel.
- Create the saturation-painting layer at the top of the layer stack.
- Choose the appropriate mask (as described in the table in the previous section) to paint through to either decrease or increase saturation and load it as a selection from the Channels palette/panel.To load a mask as a selection, Cmd + click on the mask. Marching ants will appear enclosing pixels that are at least 50% selected.
- Hide the marching ants, Cmd+H. Hiding the ants doesn’t stop the selection from controlling where paint is applied to the layer.It simply makes the ants invisible so that they don’t interfere with visually deciding how much paint to apply and where to apply it.
- Make sure the foreground color is correct for painting. Use red for increasing saturation and gray for decreasing it. Type “X” to flip the foreground and background colors.
- Choose an appropriately sized brush for painting. The left bracket ( [ )will decrease brush size and the right bracket ( ] ) will increase it.
- Feather the brush. Usually 50% or less hardness is appropriate.
- Set brush opacity to 5% or less. This is very important. Painting with red or gray at 100% opacity will always take the saturation adjustment way too far. Even 5% can be too much sometimes, but it’s a reasonable place to start. If the effect is too strong, undo the brush stroke and lower the brush’s opacity.
- Paint the appropriate areas to achieve the desired increase or decrease in saturation. The active selection (Saturation mask or Vibrance mask) will automatically restrict the paint to the proper pixels that need adjustment. Multiple brush strokes can be applied over the same area to enhance the effect.
10. Once satisfied with the adjustment, turn off the hidden selection: Cmd+D.