A tonneau cover to cover a bed or cargo box of a truck is provided. The tonneau cover includes a bulkhead panel, one or more cover panels, and at least one stack support. The one or more cover panels are foldable onto the bulkhead panel. The at least one stack support is attached to the bulkhead panel. The at least one stack support also includes a top surface that supports the one or more cover panels in a generally upright position. A first angled run is located on the at least one stack support. The first angled run is part of the top surface of the at least one stack support. A second angled run is located on the at least one stack support and extending away from the first angled run. The second angled run is part of the top surface of the at least one stack support.