IIRC almost all aluminum foil comes from recycled aluminum whereas most writing paper is virgin paper so the energy comparison is between aluminum recycling and

IIRC almost all aluminum foil comes from recycled aluminum whereas most writing paper is virgin paper so the energy comparison is between aluminum recycling and paper manufacturing. I don't remember the numbers off the top of my head, but my impression is that paper manufacturing is quite energy-intensive as well. My bet is that recycled aluminum wins out.