Adobe Photoshop

Lesson B: Knockout & Clip Mask Blending

Let’s learn two features that will let us erase some chalk drawing and leave a bit of residue.

Knockout

Use a layer’s content as a mask, a kind of layer drill.

• Open the file “concept- knockout.psd.” Parts should look familiar.
• Double-click near the top layer’s name (“scanner”). This opens the layer’s Blending Options in the Layer Style dialog.
• Lower the Fill Opacity to about 33%. Of course, the green content of the layer diminishes, but as we saw before, it leaves the effects intact. That’s why the stroke around the edges remains. Now here’s the new thing…
• Choose each of the two items in the Knockout menu (a little lower in the dialog than the Fill Opacity). Right now, both Shallow and Deep yield the ...