So many times we purchase antique documents or artwork that brings a smile to our face, only to frame it in such a way as to either decrease its value, or create harm to the piece.  Below I have outlined 10 basic points to remember when framing your piece.  This will allow for many years of enjoyment and keep your investment safe.

1. Expect that some times the cost of framing can exceed the price of an item.  A good way to look at this is to think of the framing and the materials used as part of the document or artwork.
2. The frame itself is a major part of the cost in framing.  Take time to decided and choose a frame that will enhance the document or artwork, not overpower it.  Going to a gallery to is always a good way to get ideas.  To protect the document or artwork, acid free materials should be used in matting and mounting of an item.  The most popular materials are Crescent Rag Mat and Bainbridge Alaphamat.  Double matting with a width of 2 1/2 to 3 inches is suggested for documents.
3. Hinge mount the document or artwork with archival material to the mounting board.  Never allow your piece to be dry mounted or otherwise laid down.  Dry mounting will decrease the value.
4. Matting is not only decorative, but also serves the purpose of keeping a document or piece of artwork from touching the glass.  Touching the glass can cause bonding to the glass and create damage.  Always use matting as a bridge or in the case where matting is not desired, use a plastic spacer between the document or artwork and the glass.  Never put glass on an oil painting, as this will cause the oil paint to dry and flake.
5. Light will damage a document or artwork.,  Hang the frame away from direct sunlight and if a display light is used, cover the item with a UV filter.  If cost is not an issue, then use UV glass or UV plexiglass.  Plexiglass is better than glass as it will not shatter if accidentally dropped.  Glass, if broken, will cut or scratch your artwork or document.
6. Instead of wire on the back of a frame, us a two point hanging system, such as D-Rings.  If a wire is used, hang the frame with two hangers spaced a few inches apart.  If you use the two point sytem you will never have to adjust the frame.
7. If cost is a concern, there are less expensive ways to protect your document or artwork.  Buffered mat board can be used and an acid free barrier paper can be used to between the document or artwork and the mounting board. 
8. Remember to never dry mount.
9. If you choose to not frame your document or artwork right away, always keep in a protective sleeve.

Finally, if the item you have is of such value that it would be part of an exhibt held by somewhere like The National Gallery of Art in Washington DC., then I suggest you go to the National Archives Web Site and follow their guidelines for framing.   As this is a very expensive option, save it for something that is so rare that you can not afford to not go to the expense.