Bag bottoms
I use a material in great supply after an election: those annoying political signs
made of corrugated plastic! They cut easily, are very stiff, waterproof, and
can be easily removed from the fabric sleeve I encase them. Then I use the
metal stakes to prop up plants. Reduce, reuse, recycle, and clean up litter.
It is especially satisfying to use the signs of the candidates you didn't support...