I was too cheap to buy any of the laptop bags out there for my mac, so I made one. I hope everyone can understand the instructions.
Sorry the pictures aren't that great.
*When I say cut out two rectangular pieces, you could also fold over the fabric to save sewing.
** Both of these laptop bags ended up with holes in the fabric (not along the seem). So, I would suggest using a very durable fabric.
Take two measurements, length wise and width wise. Measure your laptop along the top and the height on one side.
We will be making 3 bag shaped layers.
My measurements: (for the small MacBook Pro)
L x W
34cm X 24.5cm
This is your inside piece. I am doing my inside piece a different colour from the outside, so it will be easier to follow.
Add 3cm to the width measurement, and 6.5cm to the length measurement, so your rectangle will be (L+6.5)+(W+3). Cut out two rectangles of fabric with these measurements.
40.5 x 27.5
Line up the fabric right side to right side. Sew along three of the sides (two long, one short), leaving 0.5cm of fabric around the edge.
Test to make sure your laptop fits inside.
This layer is your cushioning. Once again add 3cm to your original measurements. From a piece of thin towel cut two rectangles (L+3)x(W+3).
*if you do not plan on making straps or a latch make the length +7
Like with layer one, only sew three of the four sides, leaving 0.5cm. Don't worry about back and front of the fabric since you won't be able to see the cushioning.
Try fitting layer two and layer one on your laptop. Take in the sides if either layer is too big. You want this piece to be as close to the first layers side as possible. Trim the edges of the towel if you do take in the sides more.
This will be the outer most layer, but it is done like the first layer. Add 4 cm to the width measurement, and 7.5cm to the length measurement, so your rectangle will be (L+7.5)+(W+4). Cut out two rectangles of fabric with these measurements.
Place your fabric right side to right side and sew 0.5cm in on the two longest sides and one of the shorter sides.
Turn layer 3 inside out, and try it on over the other two layers and the laptop. You want this layer to be very snug and as close to the size of layer 1 as possible to avoid bulging when you hem the top.
On the open edge of layer two, sew on the straps. This will keep the straps securely on and keep the inside layer from moving.
If you want to make your own straps fold a long length of fabric "hotdog" style so the fabric is right side to right side. Sew the edges together, but you can leave the ends open. Turn the roll inside out and iron flat.
Cut out two triangle like pieces. The length of one side of the triangle should be the width of the top of the laptop plus 1cm. Make sure you add the extra length of fabric onto the longest side, otherwise your latch will be too thin.
W + 1
24.5 + 1
Once again place your fabric right side to right side and sew 0.5cm in on all but the longest edge. Turn rightside out.
Make sure you consider how the latch will close. ie. put in a button hole
*if you do not sew on straps, sew the latch to the top of the second layer (as I did)
Place all your layers inside one another. Fold over the extra fabric on layers one and three and pin them together. The top of the right sides of layers one and three should now be together. Sew carefully along the top of edge of the bag.
If you have straps, sew over those, and if you have a latch place the rectangular part between layers one and three and sew.
Sew on your button to close the latch and voila!
*Some bulging may occur. It may be small enough to sew over without being noticed. If not you can do what I did and cut at an angle where the extra fabric is, continue sewing the top and later add a bow or a tie.