New materials for composition of banknotes

Hello, German Notgeld banknotes tend to be on extraordinary materials, so I wanted to ask for some more options in the drop-down field for banknote composition:

1. cardboard (example: https://en.numista.com/catalogue/note213500.html )
2. linen (example: https://en.numista.com/catalogue/note210103.html )
3. leather (example: https://en.numista.com/catalogue/note213555.html )

Thank you