Drafting the Dress Block

How to Draft the Dress Block Back

As noted in the introductory (preliminary) page, the Extended Line Dress (ELD) block is made using the Bodice Blocks and the Skirt Blocks*.  You will need a long piece of cardboard at least the full length of your Bodice Block plus your Skirt Block.

Dress Block Back – Instructions Figure 1

  1. Using your Bodice Back aligned on top of your Skirt Back block as a guide, draw a straight vertical line the approximate length of the two blocks – shown by the red line on the image.  It doesn’t matter if this line is too short or too long, it can be extended later.  This is the Center Back line – we will mark it as such after we have finished the block.
  2. Mark the approximate location of the waist is on this line. (To ensure the waist isn’t too high or low which may result in running out of cardboard).

Dress Block Back – Instructions Figure 2

  1. Draw a horizontal line at the waist level previously marked; make sure this line is at right angles to the Center-Back line. Draw this line quite long.
  2. Calculate:  (Waist measurement ÷ 4) + 0.25-in ease + 1.75-in for dart
  3. Using this measurement, measure from the CB line, along the waistline, and label the end point A.

Dress Block Back – Instructions Figure 3

  1. Place the Bodice Back on the waist line, with the Center Back of the Bodice Block lining up with the CB line drawn for the Dress Block.  The side seam at the waist level and part of the waist dart will end up a little below the waist – don’t worry about that.  Just make sure that the Center Back line is lined up.
  2. Draw around the block from the neck point around to the notch on the armhole notch. (This assumes you made the sleeve for the Bodice Block). Mark this point B.
  3. Mark the point where the side seam and armhole meets, and label it C.
  4. Mark the point where the side seam ends below the waistline, and label it D.
  5. Transfer the markings for the shoulder; i.e. the dart width and the dart point.
  6. Piece holes in the two dart points.
  7. Measure the side seam line length C~D.

Dress Block Back – Instructions Figure 4

We will now be pivoting the block to redraw the last bit of the armhole curve; this new line will meet the new side seam line we are drawing (or more closely that the original one, anyway).
  1. Holding the block down at the armhole notch point B (using something sharp that will prevent the block slipping and moving), pivot the block around until the side seam point that was below the waist, touches the waist.
  2. Using the edge of the block, trace the curve from point B to the side seam point (shown in the image with a blue dashed line), and label this new side seam/armhole point E.
  3. Remove the block from the cardboard.
Note: There is no need to mark the point on the waistline where the block touched the waist when it was pivoted; this purpose of this pivot was solely to draw the armhole curve in the correct place.

Dress Block Back – Instructions Figure 5

We will now redraw the side seam line, draw the shoulder dart and start the waist dart.
  1. Using the measurement previously taken of the original side seam (C~D), draw a line up from A towards E.  It may end a little before E, label it F.
  2. The armhole line needs to be from B~F (so that the back and front side seams match), so blend the armhole line towards F.
  3. Draw the shoulder dart: draw lines from G to H and G to I.
  4. Draw a line down from the dart point J to the waist; this is the mid-dart line for the larger waist dart.

Dress Block Back – Instructions Figure 6

  1. Place the Skirt Block on the cardboard, lining it up with the CB line and the waistline.  The side seam of the skirt will end up above the waist.
  2. Trace around the block from at the CB and hem corner, and trace around to the hip notch.  Mark the hip notch, and remove the block.

Dress Block Back – Instructions Figure 7

The last two things to do to finishing off the side seam from the waist to the hip-line, and draw the two waist darts.
  1. Using a French curve, draw the side seam line from the hip-line up to meet the waist point A.
  2. Draw the larger waist dart:
    • draw a line down from the dart point J, at right angles to the waistline, and extend it down to point  K, 6.25-inches below the waistline.  This is the mid-dart line.
    • measure a dart 1-inch wide, with the mid-dart line at the center. Label the dart edge points L & M as shown.
    • draw the dart legs.
  3. Draw a line at the underarm level, at right angles to the CB line.
  4. Draw the smaller waist dart:
    • measure 2-inches from point M towards the waist. (There are 2-inches between the darts).
    • from point M, measure towards the waist side seam and create a 0.75-inch dart. Label the dart edge points N & O as shown.
    • at the center of this dart, draw a line up and down; up to point P, which is 3-inches down from the underarm level line, and down to point Q, which is 4.14-inches down from the waist.
    • draw the dart legs.

Dress Block Back – Instructions Figure 8

You can now cut the block shape from the cardboard, remembering to:
  1. Notch the dart legs in the shoulder.
  2. Pierce holes in the cardboard at the five Dart Points,  and dart width points on the waistline.
  3. Mark the Center Back line.
  4. Mark the grainline.
  5. Label the block.


  • After you have made both Front & Back, you will need to check the side seam lengths.  The neckline and armhole have not changed (and you would have checked your Bodice Block when making it), so there is no need to check those.
  • This Dress Block is for garments with sleeves.  Note that when making sleeveless garments, garments with cutaway armholes or low necklines, you will need to make adjustments. See the section on Contouring; if you have already marked the Bodice Block with contour markings, you can just transfer them to this block.

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