If you wish to delete a Print Paper Size or Presentation option and find it is greyed out (unavailable), then the following will help with this.

The Delete button is disabled if you open the window from within the Setup Price List window. This is to prevent changes that will stop the use of the cancel option when making changes to the price list options (i.e. the option to not save your changes if not wishing to).

You will be able to delete a "Print Paper Size" and/or "Presentation Option" by accessing them directly from under the Orders menu.