Adaptation of Leonardo Da Vinci’s ‘Form’ sketch (c1490)
One of the pictorial puns in the Leonardo Da Vinci’s collection include some abstract specks / shapes. Beneath the sketch are what look the letters 'm r o f'.
Some people believe that Leonardo wrote backwards / did mirror writing.
I have added what that might look like using the online
https://www.dcode.fr/mirror-writing tool.
This sketch is produced on a piece of blue brolly fabric.