mr---Glad to help, if I can, but “concept,” to my way of thinking, is merely something of an abstract nature, very general and almost to the point of being a notion. Thus, I am not sure how something so subjective can be put forth in the form of a “paper” in a manner to effectively capture any interest or understanding. Or, "mr," we could be simply having a semantics issue here.
(1) Maybe you are referring to letter of inquiry?
“A letter sent by an organization to a prospect presenting a project for which funding is being sought and asking the prospect if they will consider funding the project or receiving a full proposal.”
See my article:
---Positioning Grant Writers For Success
(See in the Addendum: Writing Letters of Inquiry)
---And from The Foundation Center:
(2) Maybe you are referring to a statement of intention?
You develop a Statement of Intention from information provided by your organization's staff and board. The Statement will be no longer than two single-spaced pages. It will describe how the project will meet documented consensus needs and cite its benefit to the organization and community.
The Statement of Intention will attempt to apprise, enlighten, and interest prospects about the organization and the proposed project.
Those two approaches to a prospective donor are workable because they have meaningful substance and are intended to determine if there could be interest on the part of the prospect to have you tell them more and which could lead to the presentation of a full proposal.