File this under, “Now that you mention it, it’s completely obvious…” Princess seams are long shaping seams often seen in women’s dresses. They create shape in a garment with curves that model the form of the body, particularly in the area between the bust and hip, and the area between the shoulder and bust. To work properly, these seams must run over the fullness of the breast.
Long shaping seams that run over the bust begin to appear in the 15th century. Fouquet’s Madonna is the most famous example I can think of in art. In the late fifteenth century, fashion began to favor a less natural conic shape for the female torso, and long shaping seams fell out of fashion for a very long time. According to Taschen’s Fashion, the term “princess seam” originates in the 1880s:
“The princess dress was named in honor of Alexandra, Princess of Wales (later Queen of Britain). It had no horizontal waist seam, but used vertical tucks to closely fit the waist, emphasizing the bust and hips. It was fashionable around 1880, and though it was only in style for a short time, it can be seen as an example of a nineteenth century ‘body-conscious’ style.”
How They Work
Let’s take a look at a soft doll body:
This doll was created from a pattern based on princess seams. (Technically, she’s made from my Tyler clone pattern, created with my every-so-technical tin foil method.)
Now, let’s say I cut the torso pieces out and line them up nicely:
Princess seams work by removing fabric. The run over the fullest parts of the body – the bust, the outside of the hip, and the shoulder/rump. You can position them in other places, but the fit won’t be the same. The pieces will still need to accomodate the fullest parts, so wherever pieces extend past the largest parts of the body they will be, well, larger, resulting in a looser fit. (This is a really great way to sort out whether a garment with long seams was meant to fit tightly or loosely, btw, and make an educated guess about how it’s meant to reform the body. Seams off the true princess line generally indicated a looser fit. In cases without a true princess line, where all the shaping has been moved to angles in the Center Front, Side, and Center Back seams, you either have a loose fit or something is getting squooshed and rearranged – usually the bust, what with it being squishy.)
How To Read This Pattern
The horizontal tick on each piece is (roughly) where the waistline falls. The princess seams remove excess fabric where it’s not needed – primarily around the waist and above the bust. When you look at the pieces, you’ll notice that each side of of a seam (Center Front, Side, and Center Back) is a different curve. This allows the seams to closely model the shape of the body. Princess seams basically divide the body into a series of flat planes, and explain the relationship between these planes. The extreme angle of the Side Front piece above the bust point, for example, tells us that the Center Front needs to be pulled back radically to lie flat along the shoulder. Below the bust, we see that the Center Front piece has a greater angle – that tells me that this was modeled on a body with a very round bosom, because it pulls the Side Front panel towards the Center Front seam line to accommodate it. Likewise, in a very body-conscious fit (and this is), you see a distinct inward curve at the bottom of the Side Back piece – this pulls the Center Back in over the curve of the fanny.
When you look at pieces of a pattern that uses princess seams, your basically looking at portions of a silhouette. Seen from the side, the bust looks a lot like the curved seam line of the Side Front piece. Seen from the front, the silhouette resembles the corresponding side of the Center Front piece. It’s sort of like how sculptors mark out a piece of marble when they’re planning the infamous “then remove everything that’s not an elephant” trick. (This is a gross over-simplification, of course. It doesn’t help you at all with the fact that the lines of a princess seam are distorted by the length they need to accommodate the curves on the pieces they correspond with. But, you know, it’ll get you about 90% of the picture you need in your head when you’re looking at them, and that’s a pretty good start.)
The Kyoto Costume Institute, Fashion: A History From the 18th to the 20th Century. New York: Barnes & Noble Publishing, Inc, 2006.