This tablecloth clamp is designed to clamp a tablecloth ! So this clamp is designed with a ribled top side and a spring shaped bottom to secure it at the bottom with a force. Printed & tested this weekend in the rain and a low force storm on a thin PVC cloth (as in the pictures) Dimensions: 18mm & 25mm high, 25mm wide, 38mm long (or 35 for the thinner one) I used 18mm & 25mmt hick as basic dimensions, feel free to ask other thickness or lengths. The native design file is solidworks & easy modifyable. Best to use a high infill to ensure spring force.