Layer Blending modes are a set of
different algorithms that change how
the currently selected layer will interact will
the pixels from the layers below. For example,
choose the Lighten Blending mode and only
the pixels that are lighter on the current layer
KEY LAYER SKILL:
BLENDING MODES
will show through. Anything darker on the
lower layers will be visible.
It’s not always obvious what each
Blending mode will do, so it’s usually best
to experiment with different modes to
see which one suits your images.