Digital fabrication makes it easy to prototype how artifacts look, yet it remains hard to prototype how moving parts feel when used. For many 3D-printed interfaces such as lids, sliders, dials, and latches, perceived usability and quality depend on the motion’s haptic profile. This profile includes resistance, detents, damping, friction, and end-stops. While prior work offers many mechanisms and authoring approaches, designers still face a practical bottleneck. They must converge on a specific intended feel in the final object under real grip, leverage, enclosure contact, and fabrication variation. We argue that tooling should center iterative perceptual matching (IPM), where designers compare candidates in context and refine based on perceived differences rather than low-level parameters. To support this workflow, we outline two physical preview methods. Modular passive props enable fast in-object swapping of fabricated candidates. Reconfigurable haptic peripherals allow rapid programmatic exploration of candidate profiles before committing to fabrication. Building on these directions, we propose an agenda for IPM centered tools that help interpret relative feedback, choose meaningful step sizes, scale control granularity, and maintain perceptual consistency across fabrication iterations.
