Okay, so how do you define a prototype?
Here's my definition:
Regardless of its fidelity, functionality, or how it's made, a
prototype is a conceptual model that captures and communicates the
vision, intent, or idea of a design.
So, yes, in my opinion paper counts.
Cheers!
Todd Zaki Warfel
President, Design Researcher
Messagefirst | Designing Information.