Yes, the same account paper as the ledger book we are looking at, which brings up the amazing possibility that what they're looking at inside the book is a set of drawings made by Rembrandt of the ...

A Rembrandt drawing of a lion could approach ... the billionaire chairman of the precious metals asset company the Electrum Group, set up the New York-based Panthera conservation organisation.

(It’s not set at night ... nobody knew that Rembrandt used pigments in this way. Even though the discovery came to light from chemical research, it was also backed up by historical sources ...