Great job on your front pockets! today? We are talking the button fly! This might be the trickiest part of the jean: but it’s pretty easy when you break it down point-by-point. My button fly method is also beautiful – go ahead and peek inside designer jeans and compare. I dare ya!
Now, the button fly is a bit confusing when you’re first contemplating it. Your average beginner won’t be able to reverse-engineer it. And even more advanced stitchers don’t especially enjoy reverse-engineering, either! My advice is to take two 12″ squares of denim and cut the front and top of the inseam out of them, then do a sample fly as per my instructions here (minus the buttons). You can get a feel for the process, make sure you don’t make mistakes on your garment – and you can keep the fly sample for future reference.
Ready! Let’s go!
Below are the four separate units we will use, along with the pants fronts, to make the fly.
From the left we have a facing with a serged edge, a completed button fly insert (with buttonholes and contrast fabric), and two more facings stay-stitched at 1.5mm around each edge, about 1/16″ from the seam allowance. Please note the direction these are cut out, as per the direction the bottom curve faces. If you cut them out incorrectly, don’t worry – the pieces are small.
The two units at left – the serged facing and the button fly insert – will be on the left of the jean. The two units on the right will form the fly extension on the right side of the jean. The button fly insert will yield a contrast fabric peeking out on the public side of the hidden insert. If you don’t want contrast fabric involved, instead of using two facing pieces and stitching them together, use the U-shaped button fly unit as shown in the center of my cutting layout photo.
Here is how to make the button fly insert.
First, sew together the interfaced contrast fabric to a denim facing piece, right-sides together along all the long and curved edges, leaving the short top edges raw. Grade, notch (or pink, as shown):st
Turn this unit right-side out, and mark buttonhole positions. Assuming you are using 1/2″ or 5/8″ seam allowances, leave about a 1/2″ to 1″ clearance at the bottom of the fly, and a little over 1″ at the top, like so:
Now, determine your buttonhole size. Shown below: the copper button for my jean, and my buttonhole template (long ago I took all of my Singer buttonhole die sizes, and made a sample strip, so I can easily test button fit):
Now, I wouldn’t dream of sewing a buttonhole, ever, without stabilizing first. Shown below, I use a strip of water-soluble stabilizer under my button fly insert. However, even paper works. I find I get a much better buttonhole every time:
Sew your buttonhole as per your machine’s instructions. Unless you’re a buttonhole expert, now is a good time to stand up, stretch, get a cup of tea, and make up a sample (using jeans and contrast fabrics) and sew a couple buttonholes before you start!
Finished unit. Doesn’t it look great?
Shown below: the contrast-side, which in my example will be facing public-side. The stabilizer comes off easily by tearing it, and I use a needle to get the little “plug” of stabilizer out the center of each buttonhole. Even though I use a washaway stabilizer, I prefer not to get a garment wet while sewing it:
OK! How we have our finished fly unit. We’re going to move on to the right-hand side of the jean and create our clean extension. I call this an “extension” because it extends into the left side of the jean – although it could also be called a facing.
First, stay-stitch both front crotch curves on the pants fronts – about 1/16″ inside the seam allowance.
Then, pin two stay-stitched facing pieces to the jean, right-sides sandwiching the jean front with the longest side of the facing against the crotch curve. The facing curve should be facing the outseam of the jean front piece:
Stitch from the top raw edge down to the marked dot (remember our marked dot? – where the fly topstitching intersects the center front seam):
Next, cut from the raw edge of that crotch curve to the marked dot. Cut the bottom of the facing pieces diagonally, and grade the seams leaving the facing on the public side of the jeans longest, the jean front piece second-to-longest, and the inside facing piece shortest – about 1/8″:
Here’s a closeup of that intersection:
Now, this is the trickiest part of the fly – making the clean finish extension. Read through to understand the process. Please note that if for any reason you are having trouble – like your denim is too thick and your fly facings too narrow to sew the fly extension this way, you can always step from the above picture to ironing the facings wrong-sides together, and serge-finishing or zig-zagging the seam allowance (you can see this finish on the fly extension of my Kai-Jeans).
OK, so here we go. We are going to be sewing up the other long curved edge of the fly extensions, sandwiching the body of the jean in between the pieces – and sewing slowly. Sometimes I have to take the work off the machine, yank the fabric around a bit, or even flip the work over to sew from the other direction. You are sewing from that marked intersection at the center front of the jean, all the way up to the raw edge where the jean meets the waistband:
After you’ve sewn this, you will end up with a silly looking weiner-shape – part of your jean front is stuffed between the two facing pieces:
Carefully tease the jean back out of the joined facings, and iron the finished extension. Here is the public side:
And here is the inside! Doesn’t this look great?
We will set the buttons after we’ve finished the other side of the jean. Here, my buttons are merely resting on the extension:
Now, we will be putting together the left-hand side of the jean. First, affix your serged facing piece to the left-hand side of the jean, right-sides together. Stitch from the top raw edge down to the marked intersection, and carefully back-tack:
Now, press all seam allowances toward the facing, and edgestitch these layers together down to the marked intersection of facing and jean – pull both threads through, knot, glue with Fray Check, and trim. This line of stitching will face the body. You can use a contrast stitching (shown here) or a jean-colored thread:
Now press this facing to the wrong-side of the jean, and add the button fly unit, with the edge of this unit about 1/4″ from the edge of the facing fold. Go ahead and pin this unit to the left front of the jean.
Now, place the pant fronts together and sew from the fly intersection down the crotch curve, stopping at least an inch before reaching the inseams. Backtack carefully, as this seam takes a lot of stress. In the picture below, you can just barely make out this seam (in white thread) running vertically through the center of the picture:
I mark my topstitching line parallel to the front folded edge, in chalk, as shown. The topstitching will end at the fly intersection. Keep in mind, too, this topstitching needs to catch the button fly unit, as shown in the next three pictures. After stitching the one, two, or three lines of topstitching, leave the tails at the crotch long.
Shown here is the wrong side of the fly. You can see my two parallel lines of topstitching anchor the button fly unit at 1/4″ and 1/2″ from the edge. It can be difficult to line things up such that you catch the button fly unit, but don’t sew through a buttonhole. Go slow and be patient.
At this juncture, pull the tails thorough to the wrong side, knot, and thread them back to hide inside the fly unit. Seal knots with a dab of Fray Check or fabric glue:
Now, create a bar tack. The bar tack is toward the bottom of the fly, and helps hold the extension and the buttonhole side of the fly together, as shown in the next two pictures. Treat the thread tails the same as previous: pull to backside, knot, and thread the tails to hide inside the extension:
Now, mark the location of button placement by folding out the jean front with the fly closed. Buttons should be placed about 1/8″ from the center-edge of the buttonholes. Use your awl to pierce the fabric, insert the button back, and hammer. Make sure to hammer on a hard surface, not wood, to set the buttons.
Whew! You did a lot of work today! Pat yourself on the back for getting through a button fly! Next post we’ll be putting together the back pockets and the yoke, which should be nice and relaxing after this post.
Good luck! As always, post any comments here in the post, or email me.