Abstract: Sign lettering materials are described which consist of plastics film letters releasably adhered to a split backing tile, e.g. of silicone coated card, by a permanently tacky pressure-sensitive adhesive. In order to assist proper spacing of these letters (and numbers) when they are set up to form words, in the case of at least some of the letters of the alphabetic set, one or more corners of the tile has a stepped notch with one or more steps. The inmost vertical sides of the notches are abutted to give the desired spacing, consistent with the letters not overlapping. The system allows visually even spacing to be rapidly achieved over a range from closely spaced letters to wide spacing.