Diy Wooden Object Permanence Box . It was created based on the montessori method used for infants and toddlers. The object permanence box with tray features a wooden box with a hole on top which the included ball can be dropped through. Toy Box DIY Danielle from www.diydanielle.com An object permanence box is a tool for children to learn that objects still exist when no longer visible. Montessori materials are incredibly beautiful, and also very expensive. When starting with infants and toddlers there are many materials that can be modified.