Online Patternmaking Classes
by Don McCunn
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The Strapless Pattern

The strapless pattern is for a corset that extends above the bust. These instructions are a continuation of the procedures described for the rib cage portion of the corset in The Underbust Pattern. There are three basic steps to follow.

Body Wrap Body Wrap
Paper Patterns Paper Patterns
Muslin Mock-Up Muslin Mock-Up

Materials and Tools

To create a Strapless Corset, you will need the following materials and tools. These instructions show how to use an optional powernet in the side back panel to create a corset that is less restrictive than a corset that has no stretch.

Materials Tools
  • Press'n Seal (1 roll)
  • Masking tape, 3/4" & 2"
  • Pattern paper
  • Muslin (1/2 yard)
  • Powernet (1/2 yard)
  • Sewing thread
  • Rigilene boning (3 yards)
  • Eye or grommet tape (1 yard)
  • Shoe lace
  • Underwire (optional)
  • Underwire Casing (optional)
  • Basic sewing tools
  • Marking pen (optional)
  • Pencil
  • Tape measure
  • Velcro (1 yard)
  • Paper scissors
  • Fabric scissors
  • C-Thru ruler
  • Hot Knife (optional)

Create a Body Wrap

Use the steps below to create a body wrap starting from an Underbust Body Wrap. The first video for each step shows the process as a two-person operation. The second video shows it as a do-it-yourself, DIY, process.

  1. Apply Press'n Seal to the body and reinforce it with masking tape.
  2. Draw the desired design lines on the masking tape.

Applying Press'n Seal

Two Person Corset Mold

  1. Apply Press'n Seal to the center front area.
  2. Apply Press'n Seal diagonally from the side of the breast down to the rib cage.
  3. After the breast is completely covered, reinforce the shape with masking tape.

DIY Corset Mold


Draw the Design Lines

Determining the seam lines is best done before you remove the body wrap. This way you can easily follow the changes in the contour of the body. When this is a two-person operation, draw in the full design lines. When you are doing it yourself, just make marks at key reference points, then complete the lines after you have removed the body wrap.

Two Person Design Lines

  1. Draw a horizontal line at the full bust level.
  2. Extend the center front line to the above the bust level.
  3. Draw a vertical line for the apex of the bust location.
  4. Extend the seams from the body up to the top of the body wrap.
  5. Use an underwire to shape the corset cup seam.
  6. Place a narrow strip of velcro around the body above the bust and draw in the top of the Strapless Corset.

DIY Design Marks


Create the Paper Patterns

Paper patterns will be a more stable record of the corset shapes than the Press'n Seal body wrap. After you have removed the body wrap, use the steps below to create the paper patterns.

  1. Reinforce the inside of the body wrap with masking tape as described in The Underbust Pattern.
  2. Add labels and sewing notches to each shape, then cut the body wrap along the seam lines.
  3. To create the paper patterns, transfer the shapes from the body wrap.

Label and Cut the Body Wrap

Before you cut the body wrap, label each section and add sewing notches. The sewing notches are important because they are the most reliable fixed reference when you start to cut the body wrap apart. If you are working from a DIY body wrap, draw in complete design lines.

  1. Label the sections of the cup "A," "B," "C," and "D."
  2. Number the sewing notches where the cup intersects with the body of the corset.
  3. Cut the body wrap leaving the cup as a single piece.
  4. Add sewing notches to the cup and number them.
  5. Cut the cup along the seam lines.
Strapless Body Wrap Strapless Body Wrap
Corset Cup Corset Cup

The DIY Body Wrap

  1. Label the sections of the cup "A," "B," "C," and "D."
  2. Number the sewing notches where the cup intersects with the body of the corset.
  3. Cut the body wrap leaving the cup as a single piece.
  4. Add sewing notches to the cup and number them.
  5. Cut the cup along the seam lines.
  6. Add any additional seam lines that are required until all the cup pattern pieces lay flat.
Strapless DIY Body Wrap
Strapless DIY Body Wrap

Use the Body Wrap to Create Paper Patterns

The body wrap shapes can now be traced to create paper patterns. This includes verifying the length of the seam lines. The final step is to add seam allowances. If you use 3/4" (18 mm) seam allowances, the seam allowances can be used as channels for 1/2" (12 mm) boning in fitting a muslin mock-up. Use 1/4" (6 mm) seam allowances for the cup.

The Bra Cup Pattern

  1. Trace the underbust pattern created in The Underbust Pattern on pattern paper. Leave enough room between the pieces for seam allowances. The strapless shapes may require more space between the pattern pieces.
  2. Lay out the strapless body wrap pieces matching the rib cage line of the underbust pattern.
  3. Trace the shapes of the strapless body wrap pieces to the top of the underbust pattern including the sewing notches.
  4. Label the pattern pieces.
  5. Add 1/4" (6 mm) seam allowances to the corset cup patterns.
  6. Add 1/2" (12 mm) seam allowances to the top of the corset.
  7. Add 3/4" (18 mm) seam allowances to all other seams.
  8. Cut out the pattern pieces.
Completed Paper Pattern
Completed Paper Pattern

Create and Fit a Muslin Mock-Up

To verify that the pattern shapes are correct, create a muslin mock-up of the Strapless Corset. For sewing the rib cage portion of the garment, including adding boning, see the instructions in The Underbust Pattern.

The strapless corset in this example is made with a powernet side back panel for wearing comfort.

  1. Cut out the patterns.
  2. Sew the corset.
  3. Verify the fit of the muslin mock-up.

Cutting the Patterns

  1. Pin the patterns to a double layer of the fabric.
  2. Cut out the patterns.
  3. Mark the sewing notches on all pieces.
Strapless Corset Cut from Muslin
Strapless Corset Cut from Muslin

Sew the Corset

For sewing the rib cage portion of the garment, including adding boning, see the instructions in The Underbust Pattern.

Sew the Corset

  1. Sew the body of the corset using a 3/4" (18 mm) seam allowance.
  2. Sew the corset cups using a 1/4" seam allowance.
  3. As you sew the corset cup, press open each seam, zigzag the seam to the body of the cup, then trim the seam allowance.
  4. Sew the cup into the body of the corset.
Corset Cup with Trimmed and Zigzagged Seam Allowances
Corset Cup with Trimmed and Zigzagged Seam Allowances

Fit the Muslin

The final step in creating the patterns is to fit the muslin mock-up. There may be little or no fitting required. During this process, you will be able to see how the fabric works on the body so that you can make refinements for any design you may wish to create.

Fit the Muslin

  1. Lace the corset.
  2. Mark any fitting adjustments you want to make.
Front, Side, & Back of the Muslin Mock-Up
Front, Side, & Back of the Muslin Mock-Up

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Copyright © 2007, & 2020 by Donald H. McCunn