Various technologies and techniques are described that enhance ease of selection of chart styles using dynamically generated icons to represent style and templates. Weights are disposed in first and second vertical stacks on opposite ends of a base member. The system includes a first sensor configured to detect lateral positions of an upstream printhead relative to sections of a web of print media traveling through the printing system, and a second sensor configured to detect lateral positions of a downstream printhead relative to the sections of the web. The root section and neck are enveloped by a jacket having a thickness which increases from the distal side surface of the loop to the neck portion, and has an inner contour substantially aligned with the proximal side surface contour of the loop and the core.