Develop a small folded box from a paper mock-up
Develop a lightweight box around its contents, using scrap paper before cutting the final cardstock.
Start with the space inside
Set the intended object on paper and leave a little room beside it. For a first model, try an 8-by-6-centimeter base with walls 2 centimeters high. Cut a rectangle measuring 12 by 10 centimeters. The rule is simple: add two wall heights to both the base length and width. Working in centimeters makes this small example easier than converting every measurement to fractions of an inch.
Draw a line 2 centimeters in from each edge. The center is the base, surrounded by four wall strips and four corner squares. Label the base to keep yourself oriented. Ordinary paper is enough for this first version because you are checking the shape, not the final strength.
Turn the corners into tabs
At each corner, cut along just one line as far as the base rectangle. Arrange the cuts so that each long wall retains two square tabs. The short walls remain plain rectangles. Fold all four walls upward, then bend the tabs inward behind the short walls.
Hold the box together without glue. Its base should sit flat, and the walls should meet without needing to be stretched or crushed. Trim a little from the free tab corners if they protrude inside. Glue each tab to the neighboring wall only after this dry fit. Small clips can hold the joins, provided they do not leave deep dents in the cardstock.
Transfer what the model taught you
Put the intended contents in the dry model and check that you can get your fingers beside them. An object that fits the base exactly can be surprisingly difficult to remove. Write any changes directly on the model before transferring the revised measurements to your final stock.
Thicker card occupies more space at a fold than thin paper. Score it before assembly and make another test in the actual material before cutting a batch. This construction suits lightweight, dry gifts. It is not a shipping box for heavy contents or a food-safe serving container. Fit a lid separately rather than assuming it can use the same dimensions: its clearance depends on the actual folded thickness of your chosen card.
