Chest Armor

Materials Needed:

  • 1 yd of dritex/opaque white spandex
  • White thread
  • Stretch needles
  • 1/2″ white upholstery foam
  • Tailor’s chalk or water soluble fabric pen
  • Chest armor pattern piece
  • Sleeve pattern piece
  • Optional: serger

Pattern note: The chest armor pattern linked above above will fit up to about a 36-38″ bust. If you have a bust larger than this measurement OR larger than an A/B cup, you will likely need to add length along the dotted line and/or at the center back seam.

If you require more than 2-3 inches of adjustment, you’ll likely need to grade your pattern.


Grab your chest armor piece. Cut two pieces of the chest armor on the fold of your fabric. Serge or stitch the shoulders of each piece, rights sides together. You should now have 2 chest armor pieces. 


Pin your armor pieces, right sides together, making sure to match up the neckline and underbust points as well as the shoulder seams. Stitch along the entire top of the pieces and the underbust seam (If you are making a senshi with a sleeveless chest armor piece, stop a bit below the arm hole on each side. Follow this tutorial for finishing the arm hole).


Reach through your pattern piece and flip it inside out. You should now have 1 chest armor piece with a cleanly finished neckline and underbust seam.


Give it a gentle press if desired. Serge or stitch the center back seam closed, and serge around the arm holes to prevent them from shifting in the next step.


Sleeve Assembly

Go ahead and grab your foam. We use Katherine Zan’s sleeve pattern (note: this pattern is a little large for our liking, so we went down 2 sizes. E.g., if you typically wear an XL, go down to a M) for this portion.


Cut out 2 pieces of foam and 2 pieces of spandex for the sleeves. Fold your foam in half and cover it with the spandex. Pin.


Once you’ve pinned all these pieces together, baste this piece on your machine. 

Pro-tip: I find it helpful to pin from one side, then flip my piece over and stitch from the opposite side. See how the bottom side is all wrinkly? Sewing with this side up helps me control wrinkles as I stitch to minimize seam-ripping.

After basting the sleeve pieces together, trim the excess foam. You may also wish to serge or otherwise finish your sleeve to make attaching the sleeve a little easier. Using tailor’s chalk or a water soluble pen, mark 2 stitching lines on the sleeve for regular senshi or 1 line for Supers. Very carefully stitch along these lines with a straight stitch. You will want to lengthen your stitch here. We use 3.5mm.


Once your lines are stitched, check to make sure fabric is not bunched anywhere and wash away your markings.


Now it’s time to attach the sleeve to the chest armor. Pin the sleeve in place and try it on. The edge of the sleeve should come right to or just over the edge of your shoulder. Mark this position. Stitch your sleeve to the arm hole, leaving approximately a 1-2” gap at the armpit for freedom of movement. Repeat for the other side. 


Huge thanks to SparklePipsi for her tips on armor drafting and Zan for her sleeve pattern!

Tutorial text by The Geeky Seamstress. Photos by Gear Owl Photography and The Geeky Seamstress.