The first documented reference to a shipping crate in the United States is in a 1930 handbook, Technical Bulletin No. 171 written by C. A. Plaskett for the U.S. Department of Agriculture. His writing implies that crates were defined before that time. Plaskett was known for his extensive testing and defining of various components of transport packaging. The USDA Forest Service revised and expanded it in 1964 as the "Wood Crate Design Manual", Handbook 252.
There are many variations of wooden crate designs. By far the most common are 'closed', 'open' and 'framed'. A Closed Crate is one that is completely or nearly completely enclosed with material such as plywood or lumber boards. When lumber is used, gaps are often left between the boards to allow for expansion. An Open Crate is one that (typically) uses lumber for sheathing. The sheathing is typically gapped by at various distances. There is no strict definition of an open crate as compared to a closed crate. Typically when the gap between boards is greater than the distance required for expansion, the crate would be considered an open crate. The gap between boards would typically not be greater than the width of the sheathing boards. When the gap is larger, the boards are often considered 'cleats' rather than sheathing thus rendering the crate unsheathed. An unsheathed crate is a frame crate. A Frame Crate is one that only contains a skeletal structure and no material is added for surface or pilferage protection. Typically an open crate will be constructed of 12 pieces of lumber, each along an outer edge of the content and more lumber placed diagonally to avoid distortion from torque.
A crate is a large shipping container, often made of wood, typically used to transport or store large, heavy items. Steel and aluminium crates are also used. Specialized crates were designed for specific products, and were often made to be reusable, such as the "bottle crates" for milk and soft drinks.Crates can be made of wood, plastic, metal or other materials. The term crate often implies a large and strong container. Most plastic crates are smaller and are more commonly called a case or container. Metal is rarely used because of its weight. When metal is used, a crate is often constructed as an open crate and may be termed a cage. Although a crate may be made of any material, for these reasons, the term 'crate' used alone often implies one constructed of wood.