Fly Fronts

Fly Front

As I’m working on one, I thought I’d muse a bit on fly fronts.

I am not an expert, mind you. Not by a million miles, and this is not a tutorial. So long as I follow a tutorial closely, I don’t find them horrifically traumatic to put in, but how well they turn out, that varies dramatically.

First off (once again) I’ll link to my two favourite tutorials. I mostly use Debbie Cook’s because I have a hard time following video tutorials. But for those of you who like to see it in action,  Sandra Betzina has a gread video on the Threads website. It’s pretty much the same technique both times, except Debbie uses double-sided tape to hold the zipper down instead of pins.

Anyway, here are some thoughts. Insightfulness, organization, and usefulness are not guaranteed.

Cut-on vs. stitched on fly facing

This is the part of the fly that folds back to the inside to make that nice little flap that hides the ziper. The flies I’ve used in patterns all have a cut-on fly-facing. The ones in my ready-to-wear jeans all have a stitched-on fly facing. I don’t know if this reflects cutting economy (not sure how, but who knows) or if the added reinforcement of the seam is really so important that RTW feels the need to include it. It does reinforce the edge of the fly-front. I think you’d have to do the construction slightly differently, though, as I don’t think you’d baste the front seam all the way to the top before installing the zipper. On the other hand, you’d only need to add the fly facing to the overlap side, which would make it (possibly) less confusing about which side is which.

Pockets, including extensions into the fly.


I have varied a lot on the amount of interfacing I put into my flies (and how I put it in) and come to the conclusion that, at least in my opinion, more is better. Maybe if I can find some really nice beefy stretch denim it won’t matter so much, but most of the stuff I can get my hands on is fairly thin and wimpy.

Layers of interfacing: fusible and pocket-lining.

I generally interface my flies two ways: iron-on interfacing in the fly-facing area, and with fabric from the pocket extensions. Often in the same pairs of pants. I’ve tried omitting one or the other, but so far I’ve usually been happiest when I included both.

The iron-on interfacing is pretty obvious: it’s a piece cut to the same shape as the fly facing extension, plus a little bit, and fused in place. I generally do it on both sides, although I could probably do it just on the overlap side. I’ve used a variety of interfacings (woven fusible, knit fusible, Armoweft), but been happiest with a sturdy, medium-weight woven fusible; it looks like muslin with a fusible side, if you ask me. Once this is fused on, continue construction as normal.

When I was first researching making jeans, I came across the concept of pocket-extensions. Basically you re-draw you pocketing pieces so that they extend all the way to the front fly-extension. They provide sew-in interfacing to the fly and a non-stretch tummy support if that’s your thing. (My jeans run below my tummy, so I don’t really benefit from that aspect. I do like the interfacing-aspect, though.)

Extra-long zipper

A lot of people recommend using a somewhat longer zipper so you can stitch on the fly without worrying about stitching around the pull. I like this because I hate stitching around the pull (I am not a zipper queen), but also because the shortest jeans zippers I can find are about 8 cm long and as you can see from the top photo, in the rise I use the zipper opening is about 6 cm long, tops.

Yes, this is about the same as in my RTW jeans.

When applying the waistband, you use needle-nose pliers to take the teeth off where you’re stitching, and trim the zipper tape to fit. You do lose the little top-stops this way. This isn’t a problem except that if you  remove too many teeth and have a gap between the last tooth and your waistband, it is possible to pull the zipper-pull right off the top. This was the fate of these jeans. (It didn’t help that I had positioned the button wrong so they didn’t zip up easily.)

Folding back the fly shield

Fly Shield

This is a weird and mysterious rectangle of fabric you stitch to the under-lapping side of the fly, behind the zipper. It keeps zipper from catching undies/flesh/whatever, and gives the under-lapping part of the waistband something to attach to. I never even realized it wasn’t an integral part of my usual jeans until I was making a pair and actually took a good look at the fly construction. Who knew? Anyway, I always find this piece a bit suprising—oh, yeah, I almost forgot that! Now how do I put it on straight again?

Fortunately, no one will see it. The only external evidence of it is the little zig-zag bar tacks that adorn the bottom part of the fly curve in most jeans. They keep the bottom of the fly shield more-or-less in place and reinforce the bottom of the zipper.


Topstitching and Pockets

I just gave in and made a cardboard template to trace around for my fly-topstitching shape. The Jalie pattern comes with a piece, but I can never find it and usually end up free-handing the shape. Which can end up a little wonky.

Bar-Tacks on a jeans fly (and on the belt-loops, for that matter) (you can see this is one of the less-interfaced flies)

I’ve been doing the topstitching in my Featherweight, which means I can keep the Janome threaded for regular seams (which speeds things up considerably), but it does mean that it’s a little harder to do bar-tacks (those short bars of zig-zags that reinforce the pockets and help hold the fly shield in place under the fly. I guess I’ll do them at the end when I put the belt-loops on.

I am a little worried about this cotton topstitching thread’s longevity. I broke  it about fifty times while topstitching these back pockets (more shapes courtesy of my itty-bitty French Curve set). To make the design a little heavier, I stitched over it three times. I’m totally going for a bit of a free-hand, sketchy kind of look with the stitching. Totally. Not because I suck at free-motion embroidery or anything. (It’s a little better on the Featherweight, which is much happier to go slow than my Janome, but I still suck. One of these days I need to get one of those little round darning/embroidery feet to see if that helps.)

OK, I know this mostly has nothing to do with the fly front. Oops.

I need to start sketching out pocket ideas when I’m NOT in mid-construction. There are a bazillion and one cool things you can do with jeans pockets, and I never can think of any when I’m in the middle of making a pair and realize: oh, yeah, I need something cool and unique for the pockets. I managed with my cream capris, but that’s about it. Also, I need to start photographing my kids’ jeans pockets. They have some nifty, nifty pockets.

I like my pockets smallish on the theory that they make my butt look bigger by comparison. I also like them highlydecorated; according to the fashion magazines I don’t read, this is also better for those of us who are under-endowed in the derriere department. They could probably be a bit bigger than this, though, and still look fine. Thoughts for the future.

Can I just have my jeans now? I feel like it’s taking forever. I could’ve finished them yesterday, perhaps, except that we were out (are you bored of hearing this yet?) at the creek. Today is supposed to be cold and rainy, so there may be sewing hope, but I also have a house to clean.

Tyo, Fishing Queen



Filed under Sewing

15 responses to “Fly Fronts

  1. Um, this is great! And perfect timing, too. I have a few more projects to finish and then I’m tackling trousers. Have you ever drafted your own fly front? Also– the bar tacks- is that a specific stitch or do you just use the zig zag stitch on your machine?

    • It’s just a short-length zig-zag of whatever width you like.

      As for drafting a fly front, all it is is a fly-shaped (or rectangular) extension on the front crotch-curve—so yeah, it would be super-duper-crazy-easy to draft your own. Just make sure it’s at least as long and wide as you want your fly to be.

  2. I actually find that I prefer the sew-on flies when I’m doing a metal zipper. More protection from the teeth and they feel sturdier. After doing about 5 of them, I have my own version of how to make them that allows me to finish as many edges as possible and get a clean look on the inside. Maybe I should write up my method….

    I have a skirt with a side zip that drives me crazy, and now I’m thinking about how to adapt it for a fly front. I’m finding that I really prefer front zips/buttons on pretty much all my clothes.

    • I would love to hear your method! Like I said, I haven’t actually done a sew-on version yet, so I’m totally clueless about it.

      I don’t usually mind zippered skirts, but somehow pants without a fly seem creepy to me… 😉

  3. You keep posting about pants and I’ll read hiding behind a pillow. Eventually I won’t be so scared. 😉

  4. Now that’s a problem solver – an extra long zipper! What a brilliant idea. I love your creative pockets, and I’m going to steal your cardboard template idea for the fly topstitching – why didn’t I think of that before?

  5. Shams

    I like Debbie Cook’s tutorial too. LOVE LOVE the decoration on those pockets!

  6. Thanks for this, I have fabric for three pair of jeans washed and ready to be cut out…. and I have been stalling. So this should help me get going 🙂

  7. Scruffybadger

    What a great interesting post. I loved reading absolutely every detail. Really informative even though I feel aeons away from even thinking about making jeans, there’s nothing like some common sense around flies!!

    • You’ve made so many awesome pants—jeans are totally within your grasp! Unless you’re one of those people who just doesn’t wear them, in which case why would you bother—but you can totally do it if you want to! 🙂

  8. Amy

    Yay, jeans secrets! I love those pocket designs… I once tried the embroidery foot that came with my old Bernina (the only time I’ve tried quilting) and man it is so hard to control, like ice skating on a point! One probably gets used to it eventually… also, I just made a bunch of fly zippers in lightweight fabric to test out the cut-on and the sewn-on differences… not huge in terms of look but I do notice that in lightweight women’s trousers (not jeans) the facing is often cut-on. I also did both of them without basting the center front… which is actually super easy to do if you mark/notch everything correctly.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s