Scott has the short version.
The longer one is that the piece you have would have been photographed using a very large format camera. The one at the shop I worked for was built into the wall of a room, and could take negatives up to maybe 24x35 inches?
For pictures they'd use a screen in between the lens and film, to make the dot pattern (Halftone) The camera could be adjusted to make the image size whatever was needed - within reason.
those negatives were then used to make a "mask" basically a big negative made from multiple small ones, or possibly in this case, they just used the negative
Then they'd expose and develop the printing plate using the negative.
A few quick checks, to be sure it came out right, and it's off to the pressroom to be printed.
Eventually, they'd cut out the circles, and press the pins together.
|