What are they?
To produce a lamination, the picture is first mounted to high density fibre board and then covered with a clear laminate. Once it is laminated, it can be edged with a colored tape or framed without glass just like a painting on canvas. This is a great way to frame prints because you get the protection of glass without the associated problems that can arise such as breakage, glare, etc..
Since the process is not reversible, lamination is not for signed or numbered prints, or anything else that is potentially valuable or a one-of-a-kind item.
Various Laminating types are available.