I used to do this kind of work, back in the day when I was a stripper
"line repro printing" uses line art, i.e. art that is converted into lines or dots with no actual continuous tones or "grays".
This was done using a graphics (or stat) camera, whereby art could be photographed and converted into line-art using film with special screens overlaid that converted the resultant image into line art - hence the term line repro printing.
Thanks Bob-a-loo.
The process makes sense now.
From wiki...
A stat camera is a large-format vertical or horizontal stationary camera used to shoot film from camera-ready artwork. This is a large bellows-type camera which consists of the copy-board, bellows and lens, and filmboard. The vertical type can take up relatively little space, while the horizontal fills two rooms; bellows, lens, and copyboard on one side of the wall; filmboard and darkroom on the other. The type of film used is black and white "orthochromatic"; i.e., it is more sensitive to some colors than others. Guidelines, or "keylines" are created in light blue which read as white; while anything red or close to a red hue appears as black. The stat camera would be used to shoot color separations (using hue filters for each of the four process colors) and to produce halftone film for printing using a special reticulated gel mask.
While the process of capturing text and images for print is considered[by whom?] obsolete by the appearance of high-end scanners and desktop publishing, the process is still considered more efficient, since the camera itself can zoom in 300% or more and still produce a clear and clean image. There is no high-end scanner or digital camera on the market that can accomplish this goal without creating pixelization problems, or the expensive hardware to go with it. Therefore the majority of printing is text computer generated, and only then considered obsolete.[citation needed]
This process is invaluable to direct preservation of artwork, since the digital camera mimics lighting settings, and there is no scanner big enough to compass such works.
I started out learning the stat camera when I began in this industry. I did this for the last several years this method existed until computer technology came along and took over.
You could usually shoot an 80-100 page book in a few hours and you had the rest of the night to work on the tables doing screens, photos and page assembly (the fun stuff).
However, there were nights that we'd get swamped with multiple books and I'd be chained to that huge behemoth of a camera for 12 straight hours.
I had a stat cameras and I couldn't give it away after digital took over the biz.
There must a stat camera burial grounds somewhere where they went to die