How was this printed?

[MaxJ]

Hey all, thanks for taking a minute and giving your expert opinion.

I have a printed sheet on gloss paper around 120-130gsm (I'd estimate) that I would like to confirm how it was printed ie. what process litho/digital/inkjet?
I have used a Dino-Lite to take some closeups at about 75x pictured below.

The first two images are a section at the print edge on one side.
The middle two images are of some small printed text (about 2.5mm or 3/16" in height).
The last two images are of some larger text in the center of the sheet and the polarizer dialed down, so you'll see more light reflection on the sheet, and I noticed a weird artifact there - the overlapping CMYK curved lines shaped like a golf club/driver. Wondering what may be the cause of such an artifact?

Thanks in advance.

 

[Adil]

Hi sir
from your images it is clearly visible that there are dots of superimposed colors so it is an offset print this on one side
on the other hand digital printing is characterized by the variation of the brightness or a slight texture and for inkjet printing with this zoom that you did it was necessary to see parallel lines which are traces of passage of the print head
that is why I noticed that it is offset printing.
Good luck

 

[Adil]

For more details dont hesitate to contact me

 

[MaxJ]

Thanks Adil, for your feedback. So, you think it's definitely offset printed?
And what do you think may have been the cause of the 4 x golf club shaped strokes of CMYK shown in the last two images?
If I were to take a guess with my limited knowledge, because the 4 x golf club shaped artifacts are equal distance apart, and same size and shape, it could not be some foreign object on the plate. Rather, it would have to be a small fault on each plate before going to press. Maybe created in the film, or in the production of film? The item was apparently printed in the early 80's, so I'm guessing there was no direct artwork to plate process yet. Because the size and shape is almost identical, and only a tiny registration difference that is separating the colours, it seems it would likely be an artifact/contaminant on the original artwork that was imaged, like a small hair on the artwork or camera? Or even a small line in the artwork itself that was imaged. And this would mean that the artifact would appear on all prints in that same print run, yes?

Thanks, Max

 

[Adil]

exactly either a trace on the green in the exposure frame or on the film support, in relation to the offset it is a problem of identification between the 4 colors

 

[mantman]

It could be Indigo printed though looks like offset indeed