Check the 30 mm Square
Print at 100% / Actual Size on 160–180 gsm light cardstock (t = 0.22 mm). Check the bottom-right calibration box with a ruler or a US Quarter coin (Ø 24.3 mm) before cutting.
Cut Red, Score Blue
Cut along solid red outer contours. For the 3 locking slots, lightly pinch along the perpendicular tick mark and make a single snip with scissors (or slice with a craft knife).
Fold Around Your Object
Score all dashed blue lines with a butter knife or empty ballpoint pen and fold 90° inward. Place your object on the central Back Panel, wrap the walls, and tuck the Side Lock Tongue into the Keeper Slot.
Dust Flaps, Then Hook Tabs
Fold the chamfered side dust flaps inward, fold the slotted Back Flap down (at 0.50 × Depth), and tuck the Front Tongue's locking ears into the slot. Promises a neat rectangular gift enclosure, not drop protection for fragile items.