Assemble the gift box base and lid

The box is two trays of the same construction. Build the base first, learn how your cardstock behaves, then build the lid and fit it.

The two nets

Base of the medium example: 160 × 130 mm net with a 100 × 70 mm centre panel and 30 mm walls.

Lid of the same example: 131.6 × 101.6 mm net with a 101.6 × 71.6 mm panel and 15 mm walls.

Each net has a dashed rectangle around the centre panel, four walls, and four hatched tabs on the top and bottom walls with short dashed roots and small bevelled corners. Do not cut the dashed lines, and keep the bevels: they stop the tabs from jamming against the neighbouring walls.

Materials

• Cardstock of the thickness you entered as t. If you did not measure it, the default 0.3 mm is an assumption; see how to measure it.
• Knife, steel rule, cutting mat and a scoring tool.
• PVA or tacky glue, or strong double-sided tape, for the tabs.

Steps

1. Print at 100% and check the ruler. Base and lid are usually on separate sheets, possibly in different orientations; both carry the 50 mm ruler.
2. Cut the outline. Follow the solid line all the way round, including the small bevels at the tab corners.
3. Score the centre rectangle and the tab roots. Score all eight dashed lines on the inside face (the unprinted side if you printed text on the lid) so the walls fold up cleanly.
4. Fold the walls up along the centre rectangle, then fold each tab inward along its root.
5. Glue the tabs inside the side walls. Put glue on a hatched tab, raise the adjacent top or bottom wall, swing the tab inside the left or right wall and press it against the inside face. Hold until it grips, then do the other three corners. The tabs sit inside, so the outside of the box stays clean.
6. Build the lid the same way. It is shallower and a little wider.
7. Fit the lid. Turn the lid over and lower it onto the base. It should slide on with light friction and come off without pulling the base apart.

Fit troubleshooting

• Lid too tight or will not go on: increase the clearance c (per side) by 0.25–0.5 mm and print another lid only. Tabs add a layer inside the lid walls, which is why the tool warns when c is not larger than t.
• Lid too loose: reduce c in the same steps. A looser fit is often fine for a gift box; a tight fit matters more for mailing.
• Walls bow outward: the score lines were not scored deeply enough, or the stock is too light for the wall depth. Score more firmly or use a slightly heavier stock and re-measure t.
• Tabs peel: use a stronger glue, press longer, or clip the corners with small clothes pegs while drying.
• Object does not fit inside: A and B are between score lines, not the inside cavity; folding and stock thickness take a little room. Add 1–2 mm to A and B and reprint.

The calibration ruler only verifies print scale. It cannot tell you whether a lid will fit; only a sample can. Make one box, adjust, and then print the batch.