2 millimetre is the most common size for clutch pencils (or lead holders). These were much more popular years ago, but there is still a good number of clutch pencils around and there’s a good range of 2mm graphite lead available. 2mm lead is roughly equivalent to a typical wood case graphite pencil. 2mm lead used to widely available but all the well-known manufacturers stopped producing it several years ago. However, we have sourced 2mm lead in black from the Czech manufacturer Koh-I-Noor.