Wine is usually packaged for shipping and transport in wooden boxes, more rarely in sturdy boxes. The international standard quantity of boxes is 12 bottles to 0.75 liters. This amount resulted because one person can still carry it comfortably. The wine bottles are packed lying in the box. If production quantities are given in "boxes", this refers almost exclusively to boxes with 12 bottles. For longer bottle aging imaginary wines are packed in sturdy boxes made of mostly spruce wood. In the specialist trade, wines that are offered in unopened boxes are particularly valuable; they are labeled OHK = Original Holz-Kiste (English: OWC = Original Wooden Case, French CBO = Caisse en Bois Original). A box with six bottles of two different types or four bottles of three different types is called a "split case", a box with twelve different types is called a "mixed case". Packaging in boxes of six bottles is also common, the majority of which are contained upright.