Where to store the state of ribbon controls in a Word 2010 addin

I'm using Visual Studio 2010 to create a Word 2010 addin with a custom ribbon. It has various checkboxes and editboxes on it. Where do I store the state of the checkboxes and the values in the editboxes when the document is closed? Do a use an exiting d开发者_StackOverflowocument property and de/serialize it myself? Or does Word have another mechanism for this?

You could use document properties, or you might consider a Custom XML Part, which is essentially an XML document containing whatever XML you like, which is included in the docx as a part.