Creating Painterly Effects

There's an infinite number of effects you can achieve with layer masks. In this example I use a layer mask to blend a photograph and a line art version of that same image.

Figure 4.29. The original image (example A) and the finished effect combining line art and photograph (example B).

1.	Open the Daffodil image.
2.	Duplicate the background layer and apply an Unsharp Mask filter to the copy. I used an Amount of 20, a Radius of 60, and a Threshold of 0. Rename this layer "Sharpened."
3.	Duplicate the sharpened layer and choose Filter > Stylize > Find Edges to convert the layer to line art.
4.	Because Find Edges introduces distracting colors into the composition, choose Image > Adjustments > Desaturate (Command/Ctrl-Shift-U) to desaturate the layer. Figure 4.30. Find Edges applied to a duplicate layer and desaturated.
5.	Here's the good bit: add a layer mask to the Find Edges layer and paint on that layer mask. Experiment with different brush typesI used a large charcoal brush available from the Brushes paletteto reveal the yellow daffodil beneath. Figure 4.31. Painting on the layer mask of the Find Edges layers.
6.	To restore the line art edges, make a copy of the Find Edges layer, delete its layer mask by dragging its thumbnail to the Trash icon at the bottom of the Layers palette (don't choose Apply), and change the layer blend mode to Multiply. Figure 4.32. Duplicating the Find Edges layer and setting the blend mode to Multiply restores the line detail.