also known as: FSP
The moisture content at which wood cell walls are fully saturated but no free water exists. Roughly 30% MC. Wood does not move dimensionally above this point — only below.
Wood does not move dimensionally above FSP — only below 30% MC.
The percentage of water in wood by weight. Kiln-dried lumber arrives at 6-8% MC. Wood dimensional changes happen as MC changes.
The MC a board reaches in a given temperature and humidity. Each environment has its own EMC — heated homes drop to 6-8% in winter; humid summers push it to 10-12%.