From the Letterpress Forme photo group on Flickr:
A forme in letterpress printing – also known as a lockup or composition – is an arrangement of printing material and accompanying spacing material from which prints are made. The main goal of the arrangement is to keep the type and other printing material firmly in place throughout printing.
The examples here feature images of letterpress formes as part of the final design. For designs that are actually letterpress-printed, see the letterpress tag.