This is an easy and quick print, expandable wall-mounting rack for Model Master paint jars (30mm wide lid). You can add sections as you like or trim the wall brackets if you want less than three rows high. Simply print everything flat and then use super glue to attach the shelves to the vertical wall mounts. Use the wide center piece if you want more than one column.. plus two of the end pieces... simple stuff.. The jars lids sit down into the recessed opening, keeping them from sliding out.. Just lift up slightly on the jar and then pull straight out to remove. you'll need to have a print bed that can accommodate 180mm long parts.