I follow this procedure when I need to figure out the correct scale to print a PDF image at the "right size". I'm using the free Adobe Acrobat Reader, and I put the values I used in square brackets:
- Zoom in on a portion of the image that would probably be about one sheet of paper. [I selected 125% for this sample]
- Select "Print". In the window that pops up, under "More Options" select "Current View"
- Print
- Measure the hexes on the Primosole Bridge map from ASL Journal #6. [I measured 7 hexes were 6 7/8", for 0.982" per hex.]
- Measure the hexes on the sample you just printed. [I measured 9 hexes covered 10 27/32", for 1.21111" per hex.]
- Calculate the correct zoom factor: (zoom factor used) * (desired hex side) / (sample print hex size) [125% * 0.982" / 1.2111" = 101.37% ]
My margin of measurement error is larger than 1.37% so I wouldn't bother with that. You can use the "Actual Size" print option with the PDF map from MMP -- this is what I suspected all along but it's easy to check.
Now I know that when I print the whole map, I'll want to print it at "Actual Size". I would select "Print", and in the popup "Poster", "Tile Scale" 100, "Overlap" maybe 0.2 inches. Under "Page Setup" I'd choose the paper "Size" I wanted. As
@ibncalb wrote, go to a print shop, explain what you want. The map is 21.7" x 31.2" (select Print, Actual Size, and the dimensions appear above the preview). That would fit on one ANSI D-sized sheet (22"x34") or two C-sized (17" x 22") with 1" of overlap, but the printer's margins might not let 21.7" fit on 22", but there's a white margin around the map so the actual printed width you need is about 21".