Some folks I know accept as incontrovertible fact the idea that designers and print production workers cannot communicate. It bugs me. Yeah? Why not? I wonder if maybe the difficulty lies somewhere between purpose, meaning and fact?
Printers are good with facts, like ink density, spectral composition of color, dimensions and placement. They can even tell you ahead of time that folios are going to disappear when the job gets to the bindery. But they are often not so good with purpose and meaning.
But ask a printer "What two colors should I place in these equal-sized circles to give the illusion of the left one coming forward in space?" See what they say. Even if they have an answer common business sense advises them to keep it to themselves. Imagine what could happen if the designer finds the printer's answer convincing and goes with it, but when ink hits paper the illusion fails?
Isn't it ironic that most printing is based on illusion, the illusion of 3-dimensional form being rendered on a 2-dimensional surface, the appearance of full color using just 3 primary colors plus a black, and yet the very subject of visual illusion is one in which most printers are unschooled and certainly uncomfortable discussing in a business context?
But to a good graphic designer that 2-dimensional printed surface is not really a rectangle; it's more like a cube; more like our spherical Earth; a place of depths and distances, gravity, wind, balance; a world within the page containing strengths and subtleties of relationship; a place of harmonies and contrasts.