Marks splitting each page in document.

[14spar15]

Hello, I have several hundred pages of pictures in a word doc (some with a line or two of text under the picture). Each page has 2 pictures (one under the other). When the pictures are added they are different sizes and upon entry they are sized to cover about one half of the page (top to bottom). There are 15 sections in this document. Pictures are continuously being added to each section and often in the middle of a section. I would like to have some type of marker splitting each page (top to bottom) so I can size the picture to one half of the page easier when adding. I was thinking maybe one “_” on the right and left margin of each page (and each page added) would work and maybe this could be done as some type of title. The only way I’m finding to do this is in the header or footer but I don’t think that will work for me because these “_” will be about half way between the top and bottom of each page. Any ideas? Thanks