The shrinking of drying, green wood can be utilized for making different types of joints.
A shrink box is made by letting a cylinder made from green wood shrink around a dry bottom piece. Scooping out the insides of a green sapling to make boxes and vessels for storage is an old technique. Trees with decayed heart wood were often used, being easier to work. There are vessels made from hollowed trunks close to one meter in diameter. These are not shrink boxes though; the bottoms being fitted after the cylinders have dried.
Shrink boxes can be made in different shapes for different uses, like small bottles, boxes for psalm books and many other types of boxes.
Boxes made today are rarely more than 20 cm in diameter. They are mostly made from green wood from trees with a healthy core, the work starts by drilling out the bulk of the center wood to get a cylinder, and continues with knives, spoon knives or gouges. Most tree species can be used.