A portable printer having improved ergonomic and operational characteristics. The printer includes an asymmetrically-damped media centering mechanism having first and second media support members moveable along a common longitudinal axis and configured to grasp roll media. The media support members are coupled to a reciprocal movement mechanism configured to translate a longitudinal movement of the first media support member into a corresponding opposite longitudinal movement of the second media support member. A pivoting arm is coupled to the reciprocal movement mechanism. The pivoting arm pivots to a first position when the first and second media support members are moved closer to each other, which causes a damping gear to engage the reciprocal movement mechanism, thereby damping the grasping motion of the media support members and providing an improved user experience. The printer facilitates one-handed operation, including one-handed loading and unloading of media, enabling its use in a variety of environments.