how to make a backpack for school：Cut two 12 by 14-inch (30.48 by 35.56-centimeter) rectangles out of fabric. You can use any type of fabric you want, but cotton, linen, or canvas would be best, because they are durable.
You can make this bag bigger/smaller. Use the same measurements for the casing and the seam allowances, however.
Fold and press three of the edges down by ¼ inch (0.64 centimeter). Place one of the pieces of fabric down, with the wrong side facing you. Fold both of the long edges and one of the narrow edges down by ¼ inch (0.64 centimeter). Press them flat with an iron; be sure to use a heat setting suitable for the fabric you are working with.
Repeat this step for the other piece of fabric.
Use sewing pins to keep the fabric in place as you fold and iron it.
Top stitch the three folded edges down using a sewing machine. Repeat this step for the other piece of fabric. Do not sew the two fabric pieces together just yet.
how to make a backpack for school：Make the casing by folding the top, raw edge down twice. Fold the top, raw edge down by ½ inch (1.27 centimeters) and press it flat with an iron. Fold it down again by 2 inches (5.08 centimeters), and press it flat again. Repeat this step for the other piece of fabric. This will make the casing for the cord to go through.
Make sure that you are folding towards the wrong side of the fabric.
Use sewing pins to hold the fabric in place as you fold and iron it.
Topstitch the casing down, as close to the bottom edge as possible. You can use a color that matches the color of your fabric, or a contrasting one for a more interesting design. Do this for both pieces of fabric.
Sew the two fabric pieces together. Pin the fabric pieces together, with the right sides facing inward. Starting just below the casing, sew all the way around the side, bottom, and side edges of the bag, using a ⅝-inch (0.59-centimeter) seam allowance.
Leave a 1-inch (2.54-centimeter) wide gap at each bottom corner. If you forget to do this, that's okay. Simply use a seam ripper to undo some of the stitching at each bottom corner. You'll be using these gaps to slide the cording through.
Turn the bag inside out, and press it flat with an iron. Use something thin, such as a pair of scissors, a chopstick, or knitting needle to push out the seams first. This will give you a neater finish. Be sure to press all the side edges as well as the top casing.
how to make a backpack for school：Thread the cords through the casings. Attach a safety pin to one of the 58-inch (147.32-centimeter) long cords. Starting from the front-left hole, pull the cord all the way around the bag, until it comes out the back-left hole. Repeat this step with the other cord, but start at the front-right side, and finish at the back-right side.
For a fancier touch, use grosgrain ribbon. Choose a color that nicely contrasts with your fabric.
Knot the cords together. Take the two cords on the left side of the bag, and knot the ends together. Repeat this with the two cords on the right side of the bag.
Turn the bag inside out and pull the cords through the gaps you left earlier at the bottom corners. Pull the left cord through the left gap, and the right cord through the right gap. The knots should be resting just outside the seam.
Stitch the gaps close. Be sure to go back and forth over the gap a few times to hold the cords in place. Use a ⅝-inch (0.59-centimeter) seam allowance as before.
A zigzag stitch will be the best for this.
Turn the bag right-side-out. It is now ready to use! To close the back, simply scrunch the top of the bag shut along the cord. Use the two cords as straps. Keep in mind that this bag is delicate, and that it won't hold up to heavy things, like text books.