From 1967 Geoff Lawton adopted a convention of marking the tip openings with a number stamped on the side of the mouthpieces and with “STAR” (text rather than a symbol) indicating intermediate openings (half sizes). As alto and soprano mouthpieces were added to the Lawton line-up, the following standard sizes were available, although special sizes (apparently up to a marked 15 star tip opening!) could be made to custom order.
Notes on Tip Opening & Facing Measurements Tables
The facing lengths for Lawton tenor and baritone mouthpieces were not all the same as those for the Lawton-Barton equivalents of the same tip openings. The tenor facings were slightly shorter for the launch of the Lawton brand: on the baritone they did not change, except for the 0.105 tip size, whose facing was slightly shorter.
The 4 tip opening was only offered for baritone, tenor and alto from c. 1967 for a few years and was never offered for soprano.
The Lawton A4 brochures (see Marketing) included the tip opening and facing measurements but contained some anomalies:
Every edition of the brochure gives the facing length for tenor models from 9 to 10 STAR as .1000 inches where 1.000 must be intended.
The facing length for the 8 and 8 STAR tenor was .968 inches in the original and 1978 brochures but changed to .938 in those from 1989 onwards. There is then a large increment to facing length of 1.000 inches for tip opening 9 and upwards. So either the facing specification changed for 8 and 8 STAR tenor after 1978 or the brochures have an error.
Lawton-Barton and early Lawton mouthpieces were marked with a stamp on the mouthpiece table indicating the tip openings. By 1966 there were three standard tip openings for baritone and four for tenor as follows:
