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How to Duplicate a T-Shirt Pattern

This tutorial will show you how to make a copy of a t-shirt pattern from an existing shirt.


To complete this tutorial you should be familiar with


T-Shirt Torso Pattern Drafting

  1. Lay Paper down long ways with short end parallel to table and long clean end perpendicular to table.
  2. Put large piece of smooth cardboard underneath paper and have it stick out to the left at least 2”
  3. Lay T-shirt down flat and smooth facing up
  4. Find center of T-Shirt with Ruler a. Measure at the shoulders b. Measure at the chest or bottom of armhole c. Measure at the bottom hem d. Do not measure at the neck since it might not be in the center e. Put pins in the shirt vertically at each center point
  5. The shirt is likely a rectangle, and any distortion of its shape from a rectangle is likely from wearing it. There are some fitted t-shirts that are not a rectangle but are not that dramatically different
  6. Move shirt to a clean edge of the paper
  7. Pins should be directly on top of clean edge of the paper with one side of the t-shirt hanging off the edge (don’t fold the T-shirt) a. Front and back of shirt should be evenly on top of each other b. Check that the seams are on top of each other c. Make sure the shirt is flat
  8. With a pencil, draw the bottom and side of the shirt on the paper. Stop at the bottom of the armhole
  9. Draw vertical lines at the tip of armhole, bottom of arm hole and outside points of sleeve
  10. Pin armhole bottom
  11. Poke every ½” through center seam
  12. Pin through front neckline, through the rib seam
  13. At the back neck, start at the vertical line, pine through the center of the back-neck tape
  14. Remove pins
  15. Lightly sketch and connect dots with a pencil
  16. Use triangle or t square to draw 90 angles from the center at the front and back neck curves
  17. Check if there is a drop or rise on the lower hem – hem usually comes up for a fitted T
  18. Lower lines should start at 90
  19. Straighten the shoulder seam with a ruler
  20. Top of armhole seam is 90 degrees with top of shoulder
  21. Use a French curve to smooth out arm hole seam
  22. Side seam is either straight down or curved in from armhole
  23. Use French Curve to draw front and back necklines
    • Necklines must meet center at 90 degrees for 1/8”
    • As little of neckline as possible should be flat but must meet at shoulder
  24. Use clear plastic ruler and measure the length of the top and bottom necks.
    • Start at 1” on the ruler and hold the ruler vertically
    • Write down the measurements on the inside of the pattern pieces
  25. Use the ruler to measure the length if the arm hole
    • Write down the measurement on the inside of the pattern
    • Mark the center of the armhole
    • Double check by measuring from both sides of the armhole
  26. Cut out back neck void
  27. Label the pattern pieces in pen on the front of the pattern center line down to the right on the grainline
  28. Label the back void piece ( Do not lose this piece )

T-Shirt Sleeve Pattern Drafting

1.     Draw a 90 degrees L that is about 10” x 10” 2.     Put shirt upside down with top fold of sleeve on line. The top of the arm hole should be in the corner 3.     Pin through arm hole seam every ½” 4.     Measure sleeve cap armhole seam with flexible ruler. It should be the same as the torso pattern 5.     Halfway up put a notch on armhole seam 6.     Straighten lower sleeve with ruler 7.     Does not have to be 90 degrees under the arm 8.     Draw grainline perpendicular to the top 9.     Cut out the sleeve 10.  Measure the height of the rib collar 11.  Draw square rectangle double the length of front neck and void piece square off the ends – should be 15-20% smaller than the neck

Drafting Full Pattern Pieces

1.     Get new piece of Paper 2.     Lay torso piece on paper and trace around 3.     Flip over the center to mirror and trace full pattern 4.     Turn up lines and transfer armhole notches 5.     Center line becomes the grainline 6.     Add seam allowances with your clear ruler a.     ½” seam allowance is safe, add 5/8” if you want more option to change fit b.     ¼” seam allowance on neckline c.     Add ⅞” to ¾” at bottom for hem 7.     Use back void piece to draw back pattern 8.     Draw sleeve pattern, repeating the steps above

Further Reading