in depth: top down

 Today marks the official launch of our newest book, by Elizabeth Doherty: Top Down: Reimagining Set-In Sleeve Design. Preorders began last month, and print versions are now ready to ship. We wrote an introductory post about the book on July 15th; today, Elizabeth joins us for a guest post to write about her work in greater detail. Take it away, Elizabeth!

Since Top Down has come out, I've been asked to explain just what makes a sleeve 'set-in' and how the method described in the book differs from other methods for constructing top-down set-in sleeves.

 Sleeve styles are incredibly varied, and designers are always tinkering with formulas to achieve a better fit, or to create a particular style. That said, there are some tried and true shapes that have evolved over the centuries. Let's compare a few of the more common sleeves: 

A sleeve for every garment style

The most basic sleeve shape is the kimono sleeve, a simple rectangle of fabric attached to the rectangular body of the garment, with no shaping whatsoever. This style provides maximum mobility, but you may find your sleeve ends trailing in the soup occasionally. A dolman sleeve is similar, but is tapered from body to cuff, reducing excess fabric while maintaining a free range of motion. Another standard shape is the drop-shoulder sleeve. In the past this was usually a simple T-shape—like the kimono sleeve—attached to an over-sized rectangular body, but modern versions often use shoulder shaping to create a better fit.

Circular yoke designs use evenly spaced increases (or decreases) to shape the shoulder area, providing a closer, more anatomical fit, and have sleeves that are basically an extension of the yoke. A raglan garment is similar, but places all the shaping increases (or decreases) along four lines in the yoke, dividing it into a front, a back, and two sleeves. This allows for a closer fit still, and offers more freedom of movement in the sleeves.

There are also several methods for making sleeves that have the look of a set-in sleeve. One such is the 'contiguous' method. It shifts all of the increases to the sleeve portions of the yoke, creating vertical lines that mimic the armhole shaping of a set-in sleeve. Because they are worked simultaneously with the body, contiguous sleeves are really a sort of hybrid raglan.

There are many variations on these basic shapes, and probably a few more I haven't thought of, and each is appropriate to a certain type of sweater—but in my opinion, if you want a structured garment that will hang smoothly from the frame of your shoulders, you can't do better than a set-in sleeve.

What makes a sleeve 'set-in'?

In a word, it's the armhole.

The body of any set-in sleeve garment—whether knit bottom-up in pieces or top-down in one piece—will have armhole openings with straight vertical sides and curved underarms. This underam contouring allows a set-in sleeve design to fit very closely to the wearer's torso.

Once the sweater body is complete, a sleeve is joined, or 'set in' to the armhole. This may be done by sewing, as in the case of a sleeve that's been knit flat, or by picking up stitches around the armhole and working the sleeve downwards, in the case of a top-down set-in sleeve. Setting a sleeve into the completed armhole adds structure to the garment body and a creates a framework from which the sleeve can hang smoothly.

Comparing top-down methods

Knitters have been working set-in sleeves from the top since the mid 1970's. What's so different about the improved method used in Top Down? Let's look at a generic top-down formula first:

With the standard top-down method, stitches are picked up at an even rate all the way around the armhole, beginning at the center of the underarm. An initial short row is worked from the underarm, up and over the top of the shoulder to a point that's approximately two-thirds of the way around the armhole, where a wrap-and-turn is made, and then the short row is worked back to a point opposite that first turn, on the other side of the shoulder.

From this point, short rows are worked back and forth, each one going one stitch beyond the previous wrap-and-turn, and the sleeve cap grows. When all of the stitches have been worked except for the underam stitches (those that were either bound off to form the bottom of the underarm in a bottom up sweater, or cast on in a top-down design), the final short row is continued all the way around and back to the starting point in the underarm. From here on, the sleeve is worked in the round.

There are several drawbacks to this method. First, by beginning the pickup at the underam, the short row wraps on one half of the sleeve cap are always positioned one row away from the sleeve join. This means that the wraps must be picked up to hide them, though their traces are often visible in the finished sleeve cap.

The second issue is the fit of the upper sleeve cap—the part that goes over the bulge of the shoulder. If you've ever sewn a set-in sleeve garment, you'll know that you normally have a little bit of extra fabric that is eased into the upper cap when the sleeve is sewn into the body. If you pick up stitches at a constant rate all the way around the armhole, the upper cap will have too few stitches, causing it to pull tightly and flatten out right where you want a that little bit of extra fabric. And with short rows that are begun abruptly, the top of the cap can look rather square.

Third, a classic set-in sleeve that's been worked flat is recognizable by the scooped shape on each side of the lower sleeve cap. This scoop corresponds with the underarm bind-off on the body of the garment. Its purpose is to quickly reduce the bulk of fabric that would otherwise wind up under the arms. Top-down set-in sleeves made with the standard method don't provide a way of reducing that excess fabric.

Now for the improved method described in Top Down:

Here, the sleeve stitch pick-up begins at the upper cap, at the level where the first short row turn will be made. Stitches are picked up more densely in this area, then at a lesser rate as the pick-up continues down the straight sides of the armhole. In the underarm they are picked up one-for-one, providing strength in this high-stress area, and then again at the lower rate up the other straight side of the armhole, back to the start of the round.

This varied pick-up rate gives you more fabric in the upper cap area, so it doesn't have to strain across the fullest part of the shoulder, and allows the sides of the cap to fit the armhole without pulling or puckering.

The first few short rows—those that shape the upper sleeve cap—are worked with extra stitches between each wrap-and-turn, creating a smooth rounded shape at the top of the cap. The upper cap complete, the short rows turns are now made one stitch beyond each previous wrap, as in the standard method, until the lower cap is reached. Here decreases are made, contouring the sleeve closer to the underarm, and scooping away excess fabric.

What's more—since the stitch pick-up round begins where the short rows begin, each wrap abuts the sleeve join, so they don't need to be picked up. This provides a little extra reinforcement, and gives a cleaner look to the cap.

I hope this has answered some questions, and also piqued your interest in trying top-down set-in sleeves!

Six ready-to-knit patterns from the book

Stay tuned for a second guest post by Elizabeth coming this weekend!

There is also a podcast/blog tour happening from now through October. Reviews of Top Down are beginning to pop up around the knitting world—visit 2 Knit Lit Chicks and the Stockinette Zombies for their take. The Knitmore Girls have also reviewed the book in their latest episode.

Be sure to join in on our Top Down KAL over on Ravelry.

Lastly, we will be holding a giveaway contest on Pinterest next week—details to come here on the blog, as well as our e-letter (if you haven't yet, subscribe to make sure you don't miss out!).