Like their royal namesake, princess seams add a touch of elegance to any garment. Typically, they create graceful vertical lines that elongate the body and can be used for both fit and design elements. I think these seams are your best friends for pattern fitting. Sewing princess seams allows adjustment across large sections of the garment.
Moreover, these lovely seams can be let in or out to adjust shaping or create flattering curves. A princess seam should join the pattern pieces smoothly, with no puckers or gathers along the seam.
Follow these steps to learn how to sew a smooth and pucker-free princess seam!
Just what is a princess seam? This particular type of seam is a variation of darts, where the darts are manipulated to make a fitted garment using shaped seams. They can be in the bodice, skirt or a combination of both. Here is an example of how bodice darts become a princess seam. The bust dart in the side seam is rotated to the armhole, and then the darts are converted to a princess seam that goes over the bust.
Some sewing patterns now include multi-cup sizes which are really handy and can reduce the need for pattern alteration. In this example, I have used a “C” cup because it has a bit more curve than the standard pattern pieces.
Staystitch your seam allowances. Using a short stitch length, sew inside the actual seam line at about 1/8″. On a standard pattern with a 5/8″ seam allowance, you will stitch at ½”. The seam allowance is marked with a broken line, so the staystitching is inside that by the 1/8″.
In the example above, I had staystitched all the seam lines including the neckline. It helps to do the neckline staystitching at this time as well because you are going to be handling the pattern pieces, and you want to minimize the possibility of distortion.
Pin your pattern pieces together up to the notches. Be sure to mark or cut your pattern notches – they are absolutely necessary to get the proper ease and shaping on a princess seam. Leave the pattern unpinned between the notches for now.
Cut snips in the seam allowance of the center bodice seam just between the notches to allow the fabric to lay flat around the curve. Cut straight snips about 3/8″ long, and as you move the fabric the snips will open up into wedges. Be careful not to cut into your seam line.
Finish pinning your pattern pieces together between the notches. This part of the side bodice will now lay flat because of the snips (which I have marked in blue).
Stitch your seams together at 5/8″.
Press your seam allowance flat. Before you open that seam, press with the tip of the iron over the seam allowance extending about ¼ to ½” into the body of the garment.
Press your seams open. It helps to use a tailor’s ham to maintain the curved shape.
Other ways to sew princess seams include using the feed dogs of the sewing machine to ease the fabric without pins. That method takes a bit of experience and comfort with easing as you sew. If you have never sewn a princess seam before, give the method described above a try and get comfortable with creating a smooth seam. Then, you can give the “no-pin” version a whirl.
Pattern variations on the princess seam
There are many variations on the princess seam, but the sewing is fundamentally the same. A shoulder princess seam gives the best opportunity for pattern fitting, as you can adjust the shoulder width, the curve over the bust, take in or let out the waist and fit at the hip with very fine tuned adjustments.
Image via Craftsy member CatzSop
An armhole princess seam can continue all the way down the front of a dress taking the place of bust, waist and hip darts. It can even incorporate a welt pocket.
Image via Craftsy member Cissie
If you are interested in designing princess seams or changing the shape of your pattern, check out Patternmaking + Design: Creative Darts & Seam Lines with Suzy Furrer.