Framing to Blend Source Material
A frame is simply an introduction at the beginning of your quote and a follow-up statement at the end. They are the bookends that keep the quote from sliding off the shelf.
An Opening Frame is often called an "Author's Tag". It establishes the identity and credibility of your source. It also ties the quotation to the focus of your document, hinting at what you are going to reveal, explain or support.
Without a beginning frame, your reader may rightly question the authority and trustworthiness of the source of the quotation.
A Closing Frame explains how the quotation is relevant to the point being made and, in addition, shows that you are capable of expressing ideas in your own words. This is important in the process of establishing your authority as a writer.
Without an end frame, different readers may take away different ideas from the same piece of text: an unintended consequence.