Overprint vs transparency

Question

Does anyone know what is the difference between transparency and overprint?

In other words: if I print 100% cyan and then 100% magenta with 50% opacity, how is it different from printing 100% cyan and then 50% magenta with overprint?

Answer 1

Using opacity will still knockout what is below the object. Overprint, obviously, wont.

Overprint has a tendency to look like "multiply" blend mode. In fact, in many cases you can use the Multiply blend mode rather than overprinting.

Opacity tends to look much more like a mixed ink.

_{Left: 100%M set to 50% opacity. Center: 50%M set to overprint. Right: 50%M set to multiply blend mode.}