For creating digital images as art, Photoshop offers so many features that it would be difficult to single out any particular one as being the most essential or most useful. And what you use also depends on the type of art you're doing. Of course, it's knowing how to use the ensemble of Photoshop's fantastic tools that lets you realize your vision. Or, not infrequently, conjure up an image that comes as a complete surprise.
Blend modes – how a layer interacts or blends with the layer underneath — are basic to using Photoshop effectively and achieving seemingly infinite effects. Everyone who uses Photoshop regularly probably knows the groups of blend modes that darken, that lighten, that affect midtones, etc. But what I find addictive is simply running through all the blend modes on a layer to see what magic might occur.
Which is what more or less happened with the Jardin du Luxembourg image above.
