a small <#pane> of modern <#selfadh=self-adhesive> <#poststamp=postage stamps>, sold flat, but designed to be folded into <#booklet> form when the peelable strip(s) is removed. These booklets do not have separate covers. The backing paper serves as the cover. The complete unfolded convertible booklet is considered to be a <#bp=booklet pane>, and the <#liner> paper to which the stamps are attached is the booklet cover.