Dating a Coca Cola poster.

Hello
I would like to have your help dating this Coca Cola poster.
I have seen posters with the same theme but they were printed vertically.
The poster measures 15 x 11 inches
I also have difficulty understanding the type of printing used.
In your opinion what printing technique was used.
I took photos of the poster and some photos taken with a USB microscope.
Giuseppe

 

Thanks "i need help" !!!!!!
I had already seen these trays but I did not know that the drawing is a work of Sundblom which is of Swedish-Finnish origin. I live in sweden. However, they are always upright.

 

You can use the Graphics Atlas website to see magnification of different types of prints. Here is the Identification page for Graphics Atlas:
http://www.graphicsatlas.org/identification/

I looked quickly and it seems to me that the most likely possibilities are Letterpress Halftone, Offset Lithograph, or Rotogravure. All of these show some of the qualities under magnification that yours has. There are also long descriptions of how each one looks under magnification. You might need to take the poster out of its frame to know for sure.

 

Hello Figtree3
Thank you for the information. I took a look at the site and it looks like Letterpress Halftone to me too.
I removed the poster out of its frame. The paper is very thin of the type used for posters to be pasted on other surfaces.