If you go by OpenRocket material densities:
Cardboard is .68g/cm3
Paper is .82g/cm3
ABS 3D Print is 1.05g/cm3
PLA 3D Print is 1.24g/cm3
Usually I print ABS/PLA w/ 3 layers (1.2mm) thick or 2 layers (.8mm). Cardboard body tubes for Rockets are around .5mm thick. So weight ratios for surface area printed in various materials and in different thicknesses:
View attachment 528466
I printed the side pods in .8mm thick ABS so these are around 2.5x the weight of a comparable part made from .5mm cardboard. However, these ABS parts are not much more than a comparable injection molded nose cone.