Dendrochronology, also known as ‘tree-ring dating’, is a method of determining the age of a piece of wood by analysing its pattern of rings.
By measuring the thickness of a sequence of rings in the end grain of a wood panel, and comparing these to a ‘master chronology’ (summarising the average ring patterns in a particular region), it is possible to date the panel.
While dendrochronology can be used to date panels made from oak, it cannot be used for those made from poplar (most common in Italian paintings) as the growth of poplar trees is too erratic.