Artefacts often have a distinctive style or design, which developed over a period of time.
Thus, 3700 Tree-ring dating: Most trees produce a ring of new wood each year, visible as circles when looking at the cross section of a piece of wood.
The annual rings vary in size, depending on the weather conditions in each region, but they are similar for all trees of the same area.
If the sequence of rings is know for a certain area it is possible to fit in all new woods found and to date them very precisely.
In Egyptology the method was first used by Petrie for dating the Naqada period, from the development of the so-called wavy-handled pottery.
- At least some objects belonging to such a typology should be datable by other criteria to fix a typology into a chronological framework. An object category or motif might develop not regularly but in staccato 'jumps'.