4. Attach the Pieces Together: Build the Tombstone
Set your two cardboard shapes next to each other the way they will need to be attached. Line up the bottom pieces, and possible side and top flaps. If you didn’t make attached side or top flaps, now is a good time to measure and cut some out.
Then, go crazy with tape. You want this sucker to be as sturdy as taped cardboard, after all.
Don’t tape it completely closed until you put the supports and weights in.
Any tape on the outside might affect the look, so don’t get too carried away with layering.