Monotype moulds were made to very tight tolerances (less than 0.000025″ – a quarter of a tenth of a thousandth of an inch), and each was individually numbered. The following is a list of the mould style and the series number groups.
| Composition – Constant Height | 100000 |
| Composition – American Constant Height | 200000 |
| Composition – High Speed | 300000 |
| Large Composition – 14/24pt or D | S |
| Split fraction – 4/6pt | |
| Quad and Space | |
| Duplex High Quad | S |
| Duplex Low Quad | S |
| Triplex | S |
| Multigraph | |
| Palace Script | 72000 |
| Lead and Rule – 1½/3pt | 90000 |
| Lead and Rule – 6/12pt | 90000 |
| Lead and Rule – 1/3pt | 77000 |
| Lead and Rule – 4/18pt | 76300 |
| Display – 14/36pt | S |
| Display – 14/36pt | 72000 |
| Display 42/72pt | 74000 |
| Furniture – 24/72pt | 78000 |