What tool should be used with the screen/film contact across the entire film/screen surface?

The use of coarse copper wire mesh as a tool to ensure proper screen/film contact across the entire film/screen surface is founded on its ability to help evenly distribute pressure while allowing for the necessary flexibility in the imaging process. This mesh provides a consistent contact across the film, which is critical to achieving high-quality radiographic images.

The coarse characteristics of the wire allow for some spacing that ensures optimal exposure of the film while also avoiding the potential for artifacts that could arise from uneven contact. This is especially important in radiography, where image quality is paramount for accurate interpretation.

When considering the other options, a fine mesh could potentially create too much contact pressure without allowing any give, which might lead to distortion or artifacts. A plastic film holder may not provide the necessary support or pressure distribution, risking gaps in contact that could result in poor imaging. A wooden frame, while sturdy, does not mold to the film or screen and could lead to uneven contact, further compromising image quality. Thus, the unique properties of coarse copper wire mesh make it the most suitable choice for this task.