Laminating a marriage certificate is a bad idea. For all intents and purposes, it destroys the legal document. Birth certificates, marriage licenses, and other official government documents have security features that allow officials to know it is the real thing. Often this includes a raised seal that is ruined by the process of laminating. When you laminate a piece of paper, you are permanently adhering the plastic laminate to the paper, forever altering its physical makeup. If you need to protect your marriage certificate, try framing it or using a plastic document cover. That way you can take it out when you need to show it’s the real thing.