Abstract: A display letter mounting arrangement for use in an open face sign having a flat forward, or display, surface is disclosed. Each letter, or alphanumeric character, is provided on an individual flat panel which is inserted between generally horizontally oriented, parallel, upper and lower tracks. A high contrast, or illuminated, background screen is provided aft of the planar arrangement of letter panels which are positioned immediately adjacent one another. Each panel includes an opaque partition secured to a lateral edge of the panel along the length thereof so as to be positioned between immediately adjacent panels on the sign in an overlapping manner. Each partition, or inter-panel strip, has a cross section in the form of an "h", with the recessed portion thereof securely attached to the lateral edge of a panel permitting the extended portion of the partition to engage and overlap the proximal edge portion of an immediately adjacent panel.