Featured Question regarding printing process

I see these prints all the time but this is the first one I have seen with actual plate marks. I did find one with plate marks on ebay with the same frame.
I'm just curious about the differences in the printing process. The prints with the plates marks are photogravures but what process was used on the larger prints without plate marks and borders? Just a typical offset?

Here is an interesting article about the boy who posed for this painting and his daughter who has 90 copies.

http://articles.chicagotribune.com/..._1_jesus-churches-and-rectories-darlene-baker

 

Great story, and yes, he was a perfect model.

 

And, frame and all, he's on one of my walls now.

 

It's my understanding that photogravure prints come off rotary presses (it's a mass market intaglio process). As such, they don't have plate marks, but it's an easy thing to add a mark after the fact (or before, I suppose). It's just a simple bit of embossing.

Of course, I could be wrong.

Sometimes, what appears to be a plate mark will, on closer inspection, look like a wire was impressed into the paper. If you see that... it's not a true plate mark.

I have had intaglio prints that were pulled on tissue, the tissue then laid inside the plate mark impressed on a heavier piece of paper.

 

I thought the photogravures were pressed on the copper plates. I studied all these in school but it was so long ago. I can't remember what I had for breakfast so why would I remember all of this? There should be a dazed and confused emoji.

When I have more time, I will to do some more research online. Thank you.

 

I really don't know for certain, but my intuition/guess leads me to the belief that the embossed relief is intentional so it looks like a more dated process. Of course I could be wrong (I'm often wrong, on here and in life), but my logic is that I think a manufacturer would actually like to obscure press marks rather than accentuate them. The heavy embossing of this print to me suggest that this might be a post print process to either make the original print marks uniform or to add some embellishment.

 

Oh, and I'm quite sure that I'm preaching to the choir about print method identification through bleed pattern, but here's a few links some may find of interest:

https://chsopensource.org/2013/04/2...relief-and-intaglio-by-engraving-and-etching/

http://the-print-guide.blogspot.com/2010/08/how-was-it-printed-simple-ways-to.html