Draw your contoured bodice (block with darts and zero wearing ease), then draw the curved cup line from center front 2cm below bust level, to bust point, to side seam approx at same level as center front.

A full explanation on how to draw a made to measure contoured bodice, corsets and cup construction is covered in our basic blocks course/module 2.

Merge back and front at side seam to draw the halter neckline:

• start from high shoulder point and draw a line plunging down, at bust level the line is 0,5 to 1cm from center front (depending on the closure you’ll use)
• curve towards underbust dart, crossing the dart at least 10cm below bust level (this measurement depends on your bust size, so measure on you from nipple downwards the coverage you like)
• continue towards side seam, then lengthen the line 7 to 9cm past side seam on back
• square up 2,5 to 3,5cm, depending on the elastic width (line on pattern is 0,5cm more than elastic width, otherwise it won’t pass through the case)
• line crosses side seam and curve upwards, passes close to bottom part of armhole and ends on shoulder line 2,5 to 3,5cm from high shoulder point.

Lastly, change underbust dart so that it is 3cm wide at top hemline.

Now separate back and front.

Cut through curved line passing from bust point (the one you were drawing at step 1) and tape shoulder dart closed. Merge back and front at shoulder line to draw back part of halter neckline as shown (line should be as long as back neckline but less curved, or it will be gaping when wearing it). Keep the strap width consistent along all back neckline.

Cut through the lines, then tape underbust dart on front closed.

Measure the distance from back piece to center back to draw a rectangle that cases the elastic (see next step).