Rolex Explorer Ref. 1016 MK1 Fat Font ‘Frog Foot’ matte dial

Known colloquially as the frog foot because of the splayed points of the coronet, the Mark 1 dial marks Rolex’s move away from gilt dials toward the more utilitarian matte dial. The Mark 1’s had a long-lasting run: It is correct for serial ranges 15xxxxx-35xxxxx and there are also groups of examples seen in 4.4 and 5.1m range cases — thus far it’s been hard to decipher if these later serial groups are original to the watches or if these dials made their way into the cases later.

For early matte dials there are several things to note about Mark 1 examples:

• Flat handsets are seen until 1.7m
• Early lume is puffy and reacts strongly to UV. Early lume is seen on examples with serial numbers from 1.5m-1.8 or 1.9m. The UV reaction is due to the zinc sulfide phosphorescent compound that was used. Fat lume dials are an exception to this as they are not zinc sulfide but fall in this early lume range. Mark 1 examples with later serials should have very little reaction to UV
• Fat Lume Mark 1 dials are seen in the 15xxxx-17xxxxx range. These are pretty simple to pick out since the 3 / 6 / 9 lume plots of the dial look like they’ve had one too many chocolate eclairs