For weddings, anniversaries and other special occasions, exploding box cards are novel and entertaining and a great way to package a small gift, money, or a gift card. Children will especially enjoy this box card, that "explodes" when they take off the lid. While the basic design for an exploding box card is relatively easy and can be made with inexpensive and readily available supplies, your design can be as simple or complex as you like.
Take your three sheets of 12"-square card stock card stock and cut them down to size. One should be 27x27 cm, one should be 25x25 cm, and another should be 23x23cm (reference 2). With different measurements, remember to keep the card-stock square, and go down by at least 2cm or a larger increment each level.
Measure a 9x9cm square in a corner of the 27x27cm sheet. Cut it out. Trace around your square on the other three corners and cut them out. Be careful to be very exact, especially on the largest layer, as it is the outside of your box, and won't look right if you are sloppy.
Measure out an 8.3x8.3 cm square on the 25x25 cm sheet and cut it out. Trace around your square on the other three corners of your sheet and cut them out as well.
Measure out a 7.6 by 7.6cm square on the 23x23 cm sheet and cut it out. Trace around your square on the other three corners of your sheet and cut them out as well.
Use a decorative hole punch or scissors to finish the corners for extra effect.
Decorate your layers as desired. If you are using decorative paper or fabric elements, you will have to measure and cut it to size. Cut it slightly smaller for a framing effect.
Remember to decorate them inside and outside as this is a card that's seen from all angles. But don't decorate the middle square except on the top or smallest layer if you so desire.
Wait for your layers to dry. Glue the smallest layer on the middle layer. Glue the middle layer on the bottom layer.
Cut your A4 cardstock in a 13.2x13.2 inch square for a box made from 27x27cm paper. For other box sizes, divide the size of the box by two and make the lid slightly smaller. For example, for a 25x25 box, divide it by two (12.5) and then subtract a little; 12.2x12.2 is your lid size.
Make a 2cm line around the entire edge. For Your lines should intersect at the corners. Score them with your scoring tool. Cut straightly along the pencil line until it intersects with the other line. Do this only on two opposite sides.
Fold the 2cm edge carefully up and in. Glue the overlapping tabs to the inside wall of the lid. Use a clothespin to hold it in place until the glue dries.
Once you've mastered the basic exploding box shape, experiment with different shapes and sizes and extra details. Use your box card as a novel wrapping for a small gift, money or gift card. Try making a card with lots of successively smaller layers or with layers of different shapes. Make bigger and smaller exploding box cards as the occasion requires. If measurement is not your friend, templates for exploding box cards are available in craft stores and online. If you are using different sized square card stocks for your exploding box, follow this formula to find the size of your square, size of paper divided by six times two. For example, on 27cm paper, it would be 27 / 6 x 2 = 9, so a 9x9 cm square must be used. Use double-sided tape instead of glue, if you prefer.
Add weight to your layers in the form of paper, paint, pictures or other details. The explode effect on the box card comes from the weight of the layers. If your layers are too light, they may not explode as dramatically. Cut your box and your lid very exactly for a good fit and a more attractive final product. Make sure successive layers are smaller than the outer box layer. If you choose to decorate layers with paint or another wet medium, allow time for the layers to dry before gluing.