Amazing, Becky, and the prefect day for it, too. Bravo!
I saw a video on the internet a while back of a guy making solargraphs with a huge homemade camera - it was at least six feet long, on wheels, etc - and it had a big lens. He was using paper like you are. The camera had to have computer cooling fans installed because of the heat and smoke! The sun literally burned an arc into the paper. I'll try to find the video for you.
Cheers,
Jeff