Abstract: A variable volume package made from two identical or nearly identical package halves is provided. The package has integral corner posts for stack strength which are formed as the package halves are erected from blanks. The package can be used for a class of articles having two orthogonal dimensions substantially constant among articles in the class, with a third orthogonal dimension varying, by providing overlapping flaps having a length at least equal to one-half the maximum length of the third dimension and at most equal to the minimum length of the third dimension.