Gather your materials. For this case, you'll need felt, embroidery thread, a needle with a large eye or a sewing machine, a button, and scissors.
Lay the felt out. First, cut the felt down to 2 1/2" by 18". Lay your 2 1/2"x 18" rectangle of felt so the short end runs along the top.
Fold the felt. Fold the bottom of the rectangle 6 inches (15.2 cm) up.
Thread your needle. Thread the large eye needle with the embroidery thread. Tie a knot a half inch from the bottom of the loose end of the thread.
Sew a running stitch up both sides. To sew a running stitch, do the following:
* Begin by inserting the needle at the back of the bottom corner, nearest to the fold.
* Pull the thread through to the front. Continue passing the thread back and forth from the front to the back.
* Each stitch should be approximately the same length. 1/8" is a good length for this project.
* Finish with a knot in the back. Be sure to trim all of your excess thread.
* Repeat with the other side.
Use a machine optionally. If you'd like, you can use a sewing machine instead of hand sewing the sides of the felt.
Mark the spot for the button. Fold the flap forward to close the pencil case. Make a pencil mark half an inch from the bottom of the flap on the front of the case.
Attach the button. Sew a button to the front of the case just above your pencil mark. The bottom of the button should touch your pencil mark.
* Before sewing the button on, you should make a button hole stitch in the felt to reinforce the button. Do so by running the needle through the underside of the felt and up to the outside, then back in and out, making a small "x" where the button will be placed.
* You can sew the button on by placing it over the "x" and running the needle through the holes in the button and through the felt, one by one.
* Further reinforce the button by pulling the needle through the felt from the underside, wrapping it around all the stitches underneath the button, and then pulling it back through the felt.
Make the hole for the button. With a small pair of sharp scissors, cut a buttonhole on the flap. Button your case closed. All done!
* You can prevent the button hole from becoming frayed and becoming bigger over time by either stitching around the hole or applying a bit of glue around the edges of the hole. Craft stores carry a type of glue called Fray Check that is made for this purpose.