This box is very simple to make, and can be made either square or rectangular. The lid and base are constructed in exactly the same way. The first part of the instructions covering how to calculate the size of card to cut, takes far longer to explain than to do! Click on any of the photos for a closer look.
First of all, you need to measure the envelopes for the cards you will be putting into the box. Add on 0.5 or 1 cm to both the length and width of the measurement, depending on how thick the card is, and how much space you want around the envelopes. This box was made from Stampin' Up Whisper White, which is a thinner card, and I added on 0.5cm. For thicker card I would use an extra 1cm. Then you need to decide how deep you want the box to be. To do this, I stacked up the cards and envelopes and measured the height of the pile, rounding up to the nearest half cm. So now you have the measurements you need to calculate the size of the piece of card to work with.
My envelopes measure 8cm x 8cm, and the stack measured a little under 3cm. This is the calculation I did:
In the diagram below A = width of the envelope + 0.5cm i.e. 8 + 0.5 = 8.5cm
B = length of the envelope + 0.5cm i.e. 8 + 0.5 = 8.5cm
C = height of the stack of cards and envelopes rounded up to next half cm i.e. 3cm
So to calculate the size of the piece of card needed for the base of the box I did
Width C +C + A + C + C or 3 + 3 + 8.5 + 3 + 3 = 20.5cm
Length C + C + B + C + C or 3 + 3 + 8.5 + 3 + 3 = 20.5cm
Then the size of card for the lid just needs to be an extra half cm overall ie
Width 20.5 + 0.5 = 21cm
Length 20.5 + 0.5 = 21cm
So once you have done your calculations, cut out the two pieces of card to those measurements. In my case one piece 20.5cm x 20.5cm and the other 21cm x 21cm. Do the following with both pieces of card.
Measure in from each corner the height of the box (3cm for my box) and then the same amount again. Do this on all sides. Score at these measurements as shown in the photo. The extra half cm for the lid will end up allocated to the centre, which is where you need it to be.
Cut along the score lines to remove each corner as shown.
Fold and crease along each scoreline. Flatten the card back out, then score diagonally across all of the small corner squares as in the picture below.
Put double sided tape on the four edges - here I have used Stampin' Up's tape as it is a nice strong one.
Remove the covering strip from the tape, and fold in the flaps on two opposite sides, sticking them down. Doesn't matter which sides, as long as they are opposite each other.
Take one of the corners and fold in as shown.
Now fold back along the diagonal score line and press along the fold to crease well. Make sure as you do this that the fold is falling so that the corner will be nice and square. Now is the time to make any adjustments to the folds to ensure squareness. Worth taking some time here to get a good finished result.
Do the same on the other side of that edge. You need to end up with two triangles pointing towards each other on the side like this.
Remove the cover strip from the tape, and fold the flap over to cover the triangles. Press down firmly to stick in place. Do the same on the other side of the base.
Will look like this when it's finished - nice and neat.
Nice and neat on the outside too - with no 'raw' edges.
Repeat with the piece for the lid. The double thickness on the sides gives a nice sturdy finish to the box, even when thinner card is used.
Decorate the outside of the box to match the cards within.