I think it is a pretty safe guess that very few people — even comic strip enthusiasts and dedicated collectors — have no better than a very hazy apprehension of the methods that were used in “the olden days” in the printing of comic strips. I wrote a detailed post on the topic a couple of years ago. The post basically concentrated on the 1920s, and the techniques discussed could easily have applied to Connie and Vignettes of Life and Roy Powers, Eagle Scout. I’m sure that there were different techniques used at different times, and I would assume that there were different techniques used by different establishments at the same time.
Part of the problem in knowing what the methods were is that the process is really quite complex.
Pictured below is one of my Connie mats. (This does not show the entire mat.) This would have been used as a mold for the casting of metal, as a part of the process of getting the original art onto the newspaper page. The syndicate and the newspaper each made a mat as part of their end of the deal. I think this would be the mat made by the syndicate, because it includes two dailies. It is my understanding that the mats made by the newspapers would include the final version of the page (with one Connie-daily per day, six days per week).
I have three of these mats. Each has two strips — in all, a week of Connie dailies!