Design enthusiasts can convert basic jacket patterns into double-breasted versions by overlapping the centre seam panels. The double-breasted silhouette is generally associated with business attire. Made of worsted wool, this stylish cut has translated into casual wear using lightweight jersey or heavy weight fleece. Make a traditional double-breasted style with two rows of buttons or create a trendy knit version with self-fabric ties. Since most lined double-breasted jackets require tailoring techniques, like attaching jacket shells to full linings, pattern-making enthusiasts can start by making a collarless, unlined knit version.
Trace the pre-made front panel jacket pattern on pattern paper with drafting pencils. Basic centre seam jacket patterns usually consist of one front panel pattern for the right and left panels. Keep the original pattern for future projects.
Cut out the pattern tracing from Step 1 with scissors. Overlap an extra sheet of tracing paper along the centre seam, extending it a minimum of four inches. Tape the sheet with removable tape. You will shape the double-breasted jacket panel directly on the sheet in a later step. Repeat this step by flipping the pattern to the opposite side for the remaining panel. For example, if you are using the basic pattern for the right side of the jacket, flip the pattern over to make the left side of the jacket.
Place a clear graph ruler on the right front panel's centre seam. Mark the desired overlapping width on the taped tracing paper. For instance, if you want the right panel to overlap three inches, draw a vertical line 3 1/2 inches away from the centre seam, which includes the seam allowance. You will shape this extended area in a later step. Repeat this step for the left front panel.
Shape the extended right panel pattern with a French-curve ruler. Repeat this step with the left panel pattern.
Overlap the right and left panels on your table. If you are not satisfied with the shaped extension, repeat Steps 3 and 4, marking the corrected shape with tailor's chalk.
Mark the buttonhole placement on the front panel by making horizontal or vertical markings according to your button size. Repeat this step by marking the button placement on the opposite front panel. If your design does not include buttonholes, and you are making self-fabric ties, skip this step.
Transfer all notches onto the revised double-breasted pattern and snip with a notcher tool. Notches refer to pattern markings used to align fabric parts prior to construction, such as sleeves and armhole. Cut out the jacket patterns.
Pin the patterns to muslin with straight pins. This fabric type is commonly used for draping. Although you can skip this step and pin the patterns to the selected project material, using inexpensive muslin allows you to fit the garment and make draping adjustments. For instance, if you are using jersey for the jacket, select a medium weight muslin to fit and shape the double-breasted jacket.
Pin the right and left jacket panels to the back panel and fit on a dress form. Make any necessary fit adjustments by re-pinning the jacket panels, such as taking in the side seams.
Machine stitch the shoulder seams, followed by the side seams.
Repeat Steps 1 and 2 in this section by pinning and stitching the sleeves.
Turn back the raw edges along the neckline and front jacket panels. Lightly iron. Repeat this step by turning back the sleeve and bottom hem and press as well. Change the straight stitch foot to an edge-stitch foot attachment and stitch along all turned-back edges.
Fit the garment on the dress form. Overlap the front jacket panels to ensure the buttonhole and button markings align. If your design does not include buttons, skip this step and make two inch wide self-fabric ties to close the overlapped front panels.
Change the edge-stitch foot attachment to the buttonhole attachment. Make the buttonholes along the markings and slit the centre for the buttons. Sew the buttons on the remaining front panel with a hand-sewing needle and matching thread. If your design does not include buttons, skip this step.