I decided I needed to prove a point , that we had everything we needed to make one in the house already, so I set out to make my own cardboard bookshelves.
First however I cut up the main lower level box so that it had angled sides and I also cut the top of it so that it became the same depth as the top shelf.
The glue did work to keep the sections together but I just didn’t trust it to hold with all the books on it so I decided to reinforce all the joins with duct tape as well.