Leer Perfect’s “HOW TO” Charts and Diagrams: FLAT LETTER MEASUREMENTS: SUCTION CUP SIZES: Determine the best cup size based on your leer size VISIBLE OPENING Chart: Use this guide to correctly space your flat leer tracking based on your leer size. Mount your boom track first, then use the correct size spacer blocks (2 to 3 blocks) between each track as you build each row on top of the next. DISTANCE OF READERSHIP: Use this chart to determine the best leer size for your sign. NOTE: Some leers styles, like Condensed and Modern, can be more difficult to read due to their shapes, especially in smaller sizes.