A packaging article comprises first and second packaging members with one or more depressions and corresponding protrusions, respectively, and can be assembled with their each protrusion received within the corresponding depression. A transverse cross section of each depression is concave. A transverse cross section of each protrusion includes a secondary protrusion that forms a longitudinal ridge; a longitudinal cross section of the ridge comprises one or more concavities. A substantially rectangular object is place in a depression and the first and second packaging members are assembled. The object, received within the depression and located between the assembled packaging members, rests with two opposing edges of the object urged against the concave surface of the depression with corresponding lines of contact oriented substantially longitudinally, and with two other opposing edges of the object urged against the concavity.