Learn more and purchase at: deslinc.com/grout-sample-box
OUTER BOX: Locate the tabs that say "Fold This Tab First" and fold inward. This is the bottom. Next, fold the notched tabs inward until the interlock and tape them shut.
SLOTTED INSERTS:
1. Fold inserts in half using the perforated line that cross the center slots.
2. Slide the center slots into each other until the ending of the openings meet.
3. To construct the walls, fold along the perforated lines to form four interlocking cells.
4. Install folded inserts into outer box.