One piece mermaid dress with gathers


Style analysis: long dress with train, plunging neckline on front and open back. Spaghetti straps and flounce for a romantic effect. It's an interesting pattern because front and back are merged to create a single piece shaped with gathers that absorb darts volume.

Fabric: it is mandatory to use a lightweight knit - it can be mesh, tulle, lycra, jersey could work too.

Draft the pattern starting from a basic dress with darts and zero or negative ease depending on the amount of stretch the fabric has - learn how to measure it and how to calculate the right negative ease (in %) with our basic blocks course/module 2.

Step 1

Trace back and front separate, then adjust length to ground.

Raise a parallel 5 to 10cm above knee line. Take in 2cm at side seams and center back at new line, then blend to zero at hips.
Tapering above knee in mermaid style is more flattering and makes walking easier 😉

Flare at least 8 to 16cm from side seams at hemline and merge to new knee points.

In center back, create the train:

  • flare at least 20 to 30cm, connect to new knee point
  • lengthen the line by 30 to 40cm
  • redraw hemline starting at right angle in center back and blending to zero approx at side seam (depending on length and width of your train, it can be few cm before or after side seam).
Step 2

On new back and front draw the neckline:

  • start in center back at waist
  • draw a line from center back to back side seam 5 to 7cm below armpit (keep dart closed when drawing the line)
  • measure a matching point on front side seam (5 to 7cm below armpit)
  • find a point 8 to 12cm above bust level and approx 5cm inwards from armhole (this is where spaghetti straps starts), then connect to the point at side seam
  • connect neckline apex to center front approx 5cm below bust level
  • widen shoulder dart by 1cm at new neckline.
Step 3

Trace a copy of new front and back.

On front draw the slash line from bust point to center front where deepest point of neckline is.

Cut through the line and tape shoulder dart closed, opening its volume in new slash line.

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