When a model is created using dimensions measured with a standard ruler, the printed part often shrinks significantly and does not match the intended size. To address this issue, we designed a custom ruler that eliminates the need for any shrinkage compensation—simply use the same filament, and the printed object will perfectly match the real-world dimensions. The ruler features caliper-style jaws for precise positioning and dimension measurement, with a built-in clip at the top that allows measurements from both the outside and the inside.