Presumably it involved lithographic printing.
For volume it's STILL lithographic CYMK printing.
Before digital, or even colour film, you made a negative using a camera. That would be enlarged and printed on film instead of paper, or the photo-sensitised plate used directly in enlarger. Then plate developed and etched.
For colour, you make as many plates as you want (four is minimum for full colour) and use colour filters on camera.
For a while (and still some places), the digital image is printed on film in black and white (separating C Y M K or more), then plates made as in Victorian era. Better colour printing uses more than Cyan Yellow, Magenta and Black. (the film is B&W, only the ink is coloured).
Today the plate (usually a drum) can be etched direct by laser from the electronic files. Minimum for full colour is four plates / drums (CYMK), but more can be used for better quality.
Lithography has NEVER been about capture of the image, only duplication. Capture was initially by hand engraving, then photography.
The breakthrough was photoresist exposed through 1:1 film (printed instead of photo paper) or the glass plate of large format negative. Developed and washed, the exposed metal was etched with acid. It's still done today but with film printed from a digital image, using a photoplotter or special laser printer. More expensive systems use laser scanning to directly etch the drum/plate.
In the past i suppose lithography-offset technique
That's purely the reproduction of the already captured image.
In historical order
- photo camera then film to plate
- Photo camera then photo-CD (not picture CD), or scanner if A3 or smaller and flat.
- Photo camera then scan slide or negative in film scanner, or scanner if A3 or smaller and flat.
- Digital camera, or scanner* if A3 or smaller and flat.
- Rostrum digital scanner/camera (Books, stop motion animation)
- laser scanner (3D model)
A decent large format digit camera and some digital "SLR"s can manage 300dpi to 1200 dpi for larger objects. Most cheaper camera / phones only manage 300 dpi for up to about 15cm x 20cm objects.
Best quality is capture at least twice the DPI you need to distribute, so you can do anti-aliasing and noise reduction without moire patterning on print or display.
[* You can scan objects up to A2 and stitch tiles later with an A4 scanner. Larger gets tedious! Also professional scanners cope with maybe 1cm of depth, cheap USB models only handle flat documents]
EDIT
Actually from about 1851, the "fax method" was also used to put an image on a drum for printing, the original would be fixed on a same diameter drum as the print drum / plate. The two would spin on a shaft. A photo cell and high voltage arc would be on screw feed, with photo cell controlling the arc. As the drums rotated, the photo cell moved across the original and the arc etched the printing drum in sympathy. About 100 to 300 lines per inch possible.