Build a Play Stove from Recycled Laminated Cardboard

Step 4: Keep Adding Layers

The quality of the cardboard in the middle of the stack has little influence on the overall strength; it's basically there to keep the top and bottom surfaces of the plate away from each other. You can use really low-quality cardboard boxes in the middle, including those annoying yet omnipresent amazon.com boxes.

Just remember to avoid filling the gaps between pieces with glue.