Answers for the beginner, the befuddled and anyone hitting a brick wall.
Sealed with a Hiss
Q. Do you recommend laminating old documents such as birth certificates, marriage licenses, etc. to preserve them?
A. The rule of document conservation is: Never do anything that isn't reversible. Lamination is not reversible. It might be a good solution for non-archival items that receive heavy use. For example, a high-traffic restaurant might have its menu printed on one page, front and back; lamination could help menus last longer, but these items are destined for the dumpster at some point anyway. You would never want to laminate historical or valuable materials.
An alternative answer is encapsulation. This process places an item between two pieces of inert plastic (such as Mylar) and seals the plastic together (without touching the item) with double-sided tape, leaving a small opening for air. You can actually wad up an encapsulated document and it will not hurt the item (however, I don't recommend this unless you're using a throwaway item as a test).
Unlike lamination, encapsulation is totally reversible. You just cut it open (carefully!) and your document is as good as new.
Many archives will have a paper conservationist who might be willing to encapsulate a document for an individual, or you can contact the Northeast Document Conservation Center (100 Brickstone Square, Andover, MA 01810-1492, 978-470-1010).
You can also do it yourself, buying Mylar sheets or Mylar envelopes already sealed on three sides with one remaining side open through which you can carefully slide in the document.
The following companies offer Mylar envelopes and film and double-sided tape:
Once you have your supplies, you can download do-it-yourself, easy-to-understand online instructions from the National Parks Service's Conserve O Gram at www.cr.nps.gov/csd/publications/conserveogram/13-03.pdf.