Pen on printer paper.
Kurt Gödel sets the gold standard for Logic. Also, he is the coolest.
Further reading:
https://www.genealogy.math.ndsu.nodak.edu/id.php?id=19539
http://www-history.mcs.st-andrews.ac.uk/history/Biographies/Godel.html
https://en.wikipedia.org/wiki/Kurt_G%C3%B6del
Portrait of Kurt Gödel
SKU: KurtGodelD1