Shelly shirt: Sewing Instructions


The use of a serger or an overlocking foot is recommended, to keep the size of the finished seams small. If using a serger, a seam allowance of 1/2 inch (12 mm) is recommended. If using an overlocking foot on a sewing machine, or serging without the use of the knife, a seam allowance of 1/4 inch (6 mm) is recommended.

All seams, including the neckband, can be done with the same stitch, whether it be a serger, an overlock stitch, or a stretch stitch.

Hems are optional (since knit doesn’t fray), but if you do make hems, make sure they can stretch.

Make sure to use a stitch that can stretch. If sewing stretch fabric, adjust your tension to allow for extra stretch. On a serger, this will usually mean lowering the needle tension, especially the right needle, and adjusting the looper tension as needed to keep the stitch looking decent. On a regular sewing machine, lower the tension. Test your choice of stitch first on scrap fabric, and try to shape the test seam by stretching the seam along its length. It should only snap after stretching quite a bit. If it pops too easily, keep playing with your stitches/tension settings until you get something that can survive some abuse.

For making t-shirts or other shirts with 2-way stretch, regular settings with a stitch that stretches should be fine.

Step 0: Customizing and fitting your pattern

  • Select an appropriate sleeve length.

    • 10-30% for short sleeves.
    • 75% for 3/4 length sleeves.
    • 100% for long sleeves (to the wrist).
    • 115% is a good value if making a shirt with thumb holes (extends to the knuckles)
  • Select an appropriate body length.

    • Up to 80% or so will produce a crop top.
    • 100% ends at top of the hip bone.
    • 120% will produce a typical t-shirt.
    • 140% will produce a somewhat longer shirt that is less prone to untucking or riding up.
    • 200%+ can be used to make a simple t-shirt dress. It’s suggested that you set straight sides to false, and adjust the side shape (under advanced options) for t-shirt dresses.
  • If in doubt, it’s a lot easier to shorten a shirt or a sleeve than to lengthen it.

  • Figure out what kind of fit you want and set your eases accordingly. Make sure you have an appropriate fabric. If in doubt, making the shirt too loose is safer than too tight.

    • In general, when working with spandex, you want 0% to negative ease. When working with ordinary cotton/polyester t-shirt fabric, you want positive ease, both because the fabric stretches less, and because typical styles using that fabric are looser.

    • Sensory compression shirts will be the tightest / have the most negative ease.

      • 4-way stretch fabric is required. Swim fabric or another very stretchy fabric is strongly recommended.
      • Chest ease: -30% to -20%. This is the most important part to compress for sensory purposes, and is a relatively safe place to put tension.
      • Sleeve ease: -20% to -10%. Compression here can be beneficial, but you don’t want it so tight that you cut off circulation.
      • Wrist ease: -15% to 0%. Mostly preference.
      • Neck ease: 25% to 100% (25% will still be a very snug neckband that will take some stretching to get on/off the head, because of how the neckband is constructed and because neckholes usually are quite a bit bigger than the neck to fit over the head.
    • Athletic shirt

  • The author hasn’t made one yet. If someone knows what eases to use, please let me know.
    • Highly breathable fabric with some spandex/stretch is recommended.
  • Eases are somewhere between those for a compression shirt and a swim shirt.

  • Swim shirt (looser fitting stretch shirt meant for swimming)

    • Swim fabric (spandex/nylon blend or spandex/polyester blend, around 20% spandex)
    • Chest ease: ~0%
    • Sleeve ease: 0-15%
    • Neck ease: 50 to 150% (mostly a style decision). Ease under 50% isn’t recommended unless you like very snug neckbands.
  • T-shirt

  • The author hasn’t made one yet. If someone knows what eases to use, please let me know.
    • Eases will be quite a bit more larger (more positive) than for other shirt types.
  • Sweatshirt
  • The author hasn’t made one yet. If someone knows what eases to use, please let me know.
    • Eases will be similar to that for a t-shirt, or a little larger.
  • The neckband length will be mostly determined by the material of the neckband. Stretch fabric will generally use a length of around 80%. Less stretchy fabric will be longer, but always shorter than 100%, and ribbed knit (recommended for t-shirt neckbands) are around 60-70%.

Step 1: Forming the body and attaching the sleeves

  • With , sew the front piece to each sleeve along the raglan seam (the diagonal seam running from the neck to the armpit).
  • With , sew the back piece to each sleeve along the raglan seam. You should now have a single piece with a circular neck hole in the middle.

Step 2: Attaching the neckband

  • With , fold the neckband in half long ways (so it’s half as long) and sew it into a loop.
  • With wrong sides together, fold the neckband in half short ways (so it’s half as wide).
  • Turn the shirt good-side-out
  • Mark the quarter points on your neckband with ball point pins, clips, or chalk.
  • Do the same around the neck hole, marking the center of the front, the center of the back, and the midpoints on either sleeve.
  • With , line up the unfinished edges of the neckband with the edge of the neck hole, and line up the quarter points of the neckband with the quarter points of the neck hole. Stretch the neckband as needed to have all the points line up. Pin or clip the neckband around the neck hole.
  • Sew carefully around the neck hole, making sure to sew through all 3 layers.
  • Turn the neckband over. It should lay flat.

Step 3: Closing the sleeves and sides

  • Turn the shirt inside-out.
  • With , place the front and back pieces together and pin/clip their sides together.
  • With , close the sleeve and pin/clip it along the sleeve seam.
  • You should have a single seam prepared, going from the end of the sleeve to the bottom hem of the body.
  • Sew it shut.
  • Repeat for the other side.

Step 4: (Optional) Hemming

  • Hem the sleeves and/or the bottom of the shirt using a single-fold hem. Using a twin needle will add some stretch to the stitching, but in either case the use of a stretch stitch is still recommended for high-stretch fabrics.
  • Alternatively, you can overlock or serge the raw edge without folding it over to give it a little bit of substance without adding as much bulk as a folded hem, or you can make a rolled hem.
  • Or you can leave the edges unfinished, particularly if it’s swim fabric or some other fabric that does not fray at all.

Step 5: Enjoy your new shirt!

  • It’s time to take your new shirt for a swim, or to show it off at the beach!