I’m not sure I understand what you’re asking. If you are refering to cover art for disc case inserts, I would not recommend glue at all. Print the first side image of your insert aligned with the top left hand corner of the paper. Then take the printout, flip it over, and print the second side image of your insert, but this time aligning it to the top right hand corner of the paper on the other side, like so:
It won’t line up exacty, but if you oversize it by a few millimeters, you can trim the excess from the edges. It will all be on one sheet and then you wouldn’t need any glue for the insert.
If you’re talking about making a cardboard box cover for the three films (like this or this) it’s probably best to use an acid-free spray adhesive or a rubber cement.
This guide might be helpful.
This video may also come in handy, though I would not recomend using the mailing lables it shows as the adhesive probably won’t last as well as the glues I mentioned above.
That’s probably way more info than you were looking for, but hopefully some of that helps!
What brand/type of paper is recommended for these Blu-Ray cover inserts? I know I’d want something kind of thick. i.e. thicker than regular paper. So it would be more durable, and because I may print on both sides, and so I’d want less “see thru”. Also don’t want the paper to get wavy from the ink.