Anyone ever put cardboard in their LVs?

I use corrugated cardboard (from a box) and wrap it in transparent packing tape - I actually use two piece of cardboard in each of my Speedys. For my Neverfull MM, I cut out two pieces of the the brown LV box and used it for the bottom of my Neverfull - didn't wrap it since the brown cardboard looked niced already since it was an LV box. I hate saggy LV purses!