Basically this is a tutorial on how to make a turtle shell and I came up with the pattern to do it. I decided that I wanted to be a Teenage Mutant Ninja Turtle for Halloween and needed a shell to go with my costume. I did a search for DIY ninja turtle shells and was not impressed by the green painted aluminum trays.

This is an overview of everything so it won't be as detailed as the YouTube video or blog post that I put up.

Check out the video or blog for more detailed instructions if you are interested in learning more as this is a real heavy sewing DIY

Blog Post

Step 1: Download and Materials

Printing

Each page is created with an inch margin marked by the solid black box. Simply print each page out and arrange for the pattern to look like this.
Download Pattern

Materials

Sewing machine

Scissors

Pins

Fabric Marker/Seamstress Chalk

Piece A (3) – outer shell, lining, batting

Piece B (3) – 2 outer shell, batting

Piece C (3) – outer, lining, batting

Piece D (3) – outer, lining, batting

Straps (3) – 2 4x20, 1 4x40

Step 2: Cutting Your Pieces

Patterns do not have seam allowance, so give yourself ¼ - ½ inch gap when cutting the patterns out.

Piece A requires 2 pieces cut on centre fold; one will be the outer shell portion, and the other will be used to line the inside of the bag. Cut 1 piece on centre fold without seam allowance on your batting or muslin. Remember to mark the top of the pattern.

Piece B requires 2 pieces cut on centre fold with the same fabric as your outer shell. Cut 1 piece on centre fold without seam allowance on your batting or muslin. Remember to mark the top of the pattern.

Piece C and D requires 2 pieces cut on centre fold OR cut 1 piece on fabric folded twice

For the strap pieces, cut 2 rectangular pieces 4x20 inches, and 1 rectangular piece 4x40 inches

Step 3: Prep-sewing

1. Taking Piece A, sew the pleats on the wrong side of the fabric. Repeat with other piece.

2. Taking Piece B, place right sides together and sew along outside edge. Cut perpendicular to the sew line at corner curve to alleviate bunching.

3. Repeat for Pieces C and D.

Step 4: Batting

Taking batting, line the wrong sides for all Pieces A-D. Sew the batting to the pieces at the same time adding detailing to your pieces

Step 5: Strap

Take your strap pieces and fold them in half lengthwise and sew up the sides.

Take 1 of the 4x20 straps and the 4x40 strap and hem the end by folding it in twice and sewing straight across.

Take the remaining 4x20 strap that you have not hemmed and sew the centre to the outer shell

Step 6: Piecing It All Together

Flip the outer shell over and place the lining wrong side into the shell. Pin that down. Then with Piece B, pin the edges facing the right side of the outer shell. Wrap the strap piece around Piece B and pin down. Sew around the pinned piece.

Flip wrong sides out and tuck in Piece B and the strap to the centre of the bag. Pin the longer strap to the top right corner and the shorter strap to the bottom side opposite the top. Pin Piece C to the top of the inverted shell, wrong side up. Then Piece D to the bottom, wrong side up.

Sew around the whole piece and flip right sides out.