Deckle Edge - An uneven, feathery edge on a piece of paper is called a deckle edge. This edge is most commonly found on parchment invitations; however, other papers may also have deckle edges.
Layers - This term indicates layers of paper tied or glued together. If the top layer is translucent and the lower is decorative paper, you'll see a muted version of the lower layer through the translucent top.
Panel - A panel is the center section of your invitation "framed" by a raised area of paper. It also refers to pages facing each other. For example, a tri-fold invitation when opened fully, has a left, middle and right panel.
Parchment - This translucent paper is made to look like original parchment. This distinctive paper adds a softening effect to any invitation.
Vellum - Vellum is a paper with a rich, smooth finish.