McCall Pattern Company blog: Bomber Jacket Sew-Along

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A bomber jacket is not the kind of project that needs a lot of fitting. That’s one of the things we like about them! So if you don’t want to stress about fit this time around, breathe easy. You’ll probably be okay, especially if you like a slightly oversized jacket. But if you want to finesse it a bit more, we’re here for you.

Because of the relaxed overall shape, the main fitting focus for a jacket like this is going to be the shoulders and sleeves. The sleeves, obviously, because you need enough room there for comfort and movement. Getting a good fit in the shoulders will help your jacket to sit nicely and stay put through regular activity, especially if you like to wear your jackets open.

Both of our sew-along jacket patterns have raglan sleeves. If you haven’t tried fitting raglan sleeves before you might be a little bit puzzled, but it’s actually very simple. There are slight differences between the two patterns: M7100 has a dart in the sleeve cap, while B6181 does not. M7100 is also more tapered through the sleeves than B6181, so you may want to choose your pattern accordingly if you’re looking for a sleeker or blousier shape (or simply adjust the pattern to suit your preference.)

Checking the fit

You can check the fit of your jacket with a muslin, by pinning the pattern pieces together and tissue fitting, or by comparing the pieces to a pattern you’ve already fitted – whatever is most comfortable for you. For the jacket body, you mostly just need to make sure that the overall size is comfortable for the number of layers you want to wear underneath. If you usually make a full bust adjustment (FBA), you may wish to do so here as well, especially for M7100 which is designed for a slimmer fit overall (so if you want to layer a sweater underneath or add a bulky interlining for warmth you may need to go up a size).

For the sleeves, you want to make sure you have enough width for your arm and also that the angle of the shoulders works for your body. If you’re an experienced garment sewist you may already have a good idea of what shoulder alterations you need, but here are a few signs to look for if you’re not sure: If you have sloped shoulders, you may see folds from the neckline to the underarm that are caused by the shoulder collapsing. If you have square shoulders, the jacket might stand up away from your body near the neckline, and/or show strain lines at the shoulder point. When the jacket is open, the lower front edges will swing outward and away from the center.

Trial your shoulder alterations by pinching out excess along the raglan seam for sloped shoulders, or opening the center of the seam and allowing it to spread for square shoulders. Pin a strip of scrap fabric behind the opening to stabilize it so you can measure the gap. This should give you a good idea of how much you need to add or remove from the shoulder, and at what point along the seam.

M7100 has a dart in the shoulder, which helps to give it a more fitted shape. While fitting, check to make sure this dart is ending in the right place. You may want to make it longer or shorter if you have particularly wide or narrow shoulders, or move the point of the dart forward or backward if you have forward or very upright shoulders. When fitting this area, take a photo or have a friend check to make sure the dart is in the right spot, as turning your head to look will throw it off.

My jacket muslin, after altering.

My M7100 muslin, after adjustments.

I’ll be using M7100 for my jacket. I checked the fit by pinning the front and back to the sleeve along the stitching line, then comparing the pieces to a non-raglan pattern I’d already fitted. When you match the pieces up along the center front/center back, the shoulder seams of the comparison pattern should line up with the edges of the dart on M7100. I ended up needing a 5/8″ square shoulder adjustment in the front and none in back, which gave me the correct shoulder angle and put the dart in the right place for me. I also added about 3/4″ to each side of the sleeve at the wrist, to make it a little blousier above the cuff, and may take a little bit of length off the hem and sleeves as I’m only 5’4″. The fabric is a heavy double-faced polyester satin with yellow threads in the warp and black weft.

Before You Alter

Before we dive into the pattern alterations, a quick note: the easiest way to account for sloped shoulders is with a small shoulder pad. This may reduce or eliminate the need to alter the pattern (though you may need to lower the armhole slightly for thicker pads, to ensure there’s still enough room for your arm). For raglan sleeves, you’ll want a raglan pad that curves over the end of the shoulder and creates a soft, continuous line.  Cover the pads in matching or coordinating fabric for an unlined jacket, or if you’re adding a lining you can slip the pads inside. If you don’t like the look of shoulder pads on yourself, or if you have square shoulders, you’ll find details on adjusting the pattern’s shoulder angle below.

Mark sleeve horizontally and vertically before altering

Mark sleeve horizontally and vertically before altering

Most of the alterations I’m going to talk about will work for both jacket patterns, as they largely ignore the shoulder dart. For all sleeve alterations, draw a line across the base of the sleeve cap, between the underarm points. Draw a second line perpendicular to the first, extending from the stitching line at the neckline to the stitching line at the wrist, right down the center of the sleeve (If using M7100, it should pass through the center of the dart.) Then read the section corresponding to your specific alteration to see where to cut.

Bicep fit: Adding or Removing Width

To adjust the bicep without changing the length of the seam or the angle of the shoulder, start by drawing a line across the sleeve cap, perpendicular to the grain. This is to indicate where the end of your shoulder is – if you’re using M7100 it will be approximately at the level of the dart point, but if you’re using B6181 you should mark this point while fitting the muslin or tissue.

Slash down the center of the sleeve from neckline to wrist and across from underarm to underarm, stopping at the stitching line for each. From the point where the cuts intersect, also cut at an angle up to the point where your shoulder line intersects the front and back seams.


Widening a raglan sleeve

To make the upper arm wider, spread the front and back apart to create a ‘Y’ shape opening, allowing the upper and lower sleeve pieces to overlap at the underarm line. You will need to pleat out a little excess length in the seam allowance at the wrist and front/back seams, and snip into the seam allowances to release the tension at the underarm.

Making a raglan sleeve narrower through the bicep

Making a raglan sleeve narrower through the bicep

To make the arm narrower, overlap the front/back pieces above and below the underarm line, allowing them to spread vertically. Snip the seam allowances at the front/back seams and wrist and pleat out the excess at the underarm.

Finish by taping the overlaps in place, then filling in the gaps with paper or leftover pattern tissue. Redraw the cutting lines in the altered areas to smooth out the curves.

Square or Sloped Shoulders

There are two ways to adjust the shoulder angle of a raglan sleeve: by adjusting the body of the jacket and by adjusting the sleeve itself. Adjusting the sleeve is a little more straightforward, but especially if you’re making a large alteration it’s a good idea to make your adjustments on the body in order to preserve the proportions of the jacket and the size of the arm opening.

To adjust the shoulder angle via the sleeve, slash the pattern from underarm to underarm, and diagonally to both midpoint/shoulder level (as was done in the previous alteration) and to the top corner of the sleeve by the neckline. Do not cut along the length of the sleeve unless you also want to change the bicep width.


Altering the raglan sleeve for square shoulders (left) or sloped shoulders (right)

Make the shoulders more square by spreading at the neckline and underarm slashes and overlapping at the midpoint  slashes. To make the shoulders more sloped, spread at the midpoint slashes and overlap at the neckline and underarm slashes. If you wish to also make the bicep wider or narrower, cut from the underarm line down to the wrist and spread or overlap there as well. Tape the overlaps in place and fill the gaps with scrap tissue, then smooth out the curves as above.


Adjusting a raglan-sleeve jacket for square shoulder (left) or sloped shoulder (right). Shown on M7100.

Sometimes it’s better for the overall proportions of the jacket to adjust the body instead of the sleeves. To do this, slash just below the stitching line along the length of the raglan seam. For M7100, remember that you will need to adjust the side front and front the same amount at the side front seam, so that they will still match up correctly after altering. Clip to the stitching line as shown at left above so that you can shape it into a curve, as the widest point of the spread or overlap will be near the middle of the seam (again, you can determine how much and where to spread by making a muslin). Note that the front and back raglan seams may need to be adjusted different amounts – this is fine, as long as you make sure they still match up at the side seam.

Shortening a sleeve seam on M7100 (left) or lengthening (right)

Shortening a sleeve seam on M7100 (left) or lengthening (right)

After repositioning the raglan seam on the body, you will need to add or remove a little length so that it still matches up with the rest of the piece, and add or remove the same amount on the sleeve piece so that the raglan seams remain the same length. On B6181, do this by cutting straight across the sleeve cap and spreading or overlapping. On M7100, you can do it by changing the angle of the shoulder dart: cut from the raglan seam to the point of the dart, and slash the dart down the center. Pivot around the dart point to add or remove length from the raglan seam while making the dart wider or narrower. Finish by filling the gap with scrap paper and smoothing out the curve as above.

Removing the Shoulder Dart

removing the dart from a raglan sleeve

If you want to remove the shoulder dart entirely from M7100, it’s easy enough to do. Cut along the line from underarm to underarm. Then, cut perpendicular to that line down to the wrist edge and up to the point of the dart. Snip into the seam allowances at the underarm and wrist, leaving tiny bits of paper as hinges. Fold the dart closed, tape in place, and fill in the gap with excess tissue. Note that the (now dartless) sleeve will be quite a bit wider than the original, but the actual shoulder angle will be the same. You may or may not wish to make additional fitting alterations; if so refer to the instructions above.