A client interested in conservation turned up at my door to discuss framing some Swedish stamps. He requested that they be handled only with gloves (hand oils), that they be mounted without any adhesive whatsoever, and that the stamps be floating in the framing design.
To float an item in framing terminology means to display every square micrometer of the item. Most often, items are matted, which means that an opening is cut in a mat to reveal the image. The opening is generally cut 1/8" - 1/4" smaller than the item to slightly cover the edges. This holds the item down and gives a sharp edge. Normally, items with unusual or interesting edges are floated so those characteristics can be viewed. The deckled edge of a stamp is a great example. Adhesives must be used in a float design. How else would the item stay up?
And then I remembered that my old buddy Chas had taken a class in encapsulation. A new mounting technique that is adhesive-free. Even in a float situation.