Sorry for the late response, I was away from the computer most of the weekend.
I’ll respond to your direct message.
I was thinking of using post it notes. Just turn them upside down, adhere half to each of the boards (underneath). When done simply remove, no damage to the boards.
I’m not sure that post-it notes would have enough “ummph” to hold the board together??
I just used some painters tape. A few small pieces on the seams and it was perfect. When done just remove tape and store the boards on the box.