A dual-material vacuum cup for a vacuum-based end effector includes a bellows having a proximal end configured for connection to the end effector and a distal end. The bellows also defines a pathway for a flow of air. A lip is connected to the distal end of the bellows, the lip defining an opening in fluid communication with the pathway for the flow of air. An insert is then connected to a distal end of the lip, and the insert is in fluid communication with the opening defined by the lip. To engage parcels of various dimension and construction, the lip is composed of a first material (such as silicone rubber or another elastomeric material), while the insert is comprised of a second material (such as a foam material).