Red Pants — The French Fly, Oui!

I just don’t make enough pants to ever get comfortable with the zipper. So I crawl through the process. Somehow it all comes together, but it remains a mystery in the end.

The Jedediah pattern has a perfectly fine zipper fly, but for this project I really have my heart set on a French fly. The French fly has an extended right fly shield that buttons into the waistband. It’s a nice touch which probably, in the end, doesn’t accomplish anything more than adding a step to getting dressed in the morning. Still, it looks great on the inside of the pants; especially when a contrasting fabric is used. It will require some careful planning. So I’ve consulted my very limited menswear resources — Roberto Cabrera’s text on menswear tailoring, David Coffins book, Making Trousers, and the instructions and pattern pieces from a vintage Bill Blass suit pattern.

The Jedediah pattern features what’s known as a “cut on fly shield”. There are extensions at the center front that get folded back to create the upper overlap that conceals the zipper. It’s a great way to reduce bulk, but the edge of the fly can seem a bit “wimpy” IMO. The alternative is to sew an extension on, under stitch it and then fold it back to create the overlapping part of the fly. The two decent pair of RTW pants that I own (Calvin Klein and Kenneth Cole) are constructed this way. It just makes for a more substantial edge at the fly opening.

I always like to experiment before I launch into the unknown. So I made a little mock up with some scraps just to check the potential “bulk issue” of a sewn on fly. I think this will make a terrific fly, so it’s full steam ahead.

Off come the extensions! No turning back now. On the right side I’ve basted a line at 3/8″. This will be folded back and stitched close to the zipper teeth. This assures that the zipper will be set back 1/4″, and that none of the zipper tape will be visible. Pet peeve — when the zipper tape is visible at the bottom of the fly!

This is where I really have to put my thinking cap on. Using the pattern from the Bill Blass suit, I drafted a new right French fly. (The original Jedediah pattern is on the left for comparison). Eventually there will be a button hole in the upper left corner of the new fly. BTW there is an excellent article in the current Threads magazine concerning industry standard seam allowances. We waste SO much time and effort trimming seams. I smartened up this time and drafted my pattern with 1/4″ seams. Yes, you can teach an old dog new tricks!

The left fly is created from the new right fly by just lopping off the extension for the buttonhole. This little bit is lined with a scrap of bemberg rayon to reduce bulk. It doesn’t get much thinner than that. In the end, none of it is ever visible, but it provides a nice clean finish to the left side of the zip.

One bit gets sewn to another bit, then another bit … then flip here, sew here….. have I mentioned how the whole process baffles me?

Lastly, I draft a right fly lining that will extend up onto the waistband, God willing. The right edge will fold over the seam allowance to provide a clean finish. (Just basted in place for the time being).

The completed French fly, outside and inside. Of course NONE of this was ever necessary. But shouldn’t the clothes we make give us pleasure, and to the extent they can, fulfill our dreams?

Here’s to making our sewing dreams come true.

6 thoughts on “Red Pants — The French Fly, Oui!

  1. Wow, these are looking incredible!
    I know what you mean about the fly, I’ve done quite a few I suppose, and no two are the same!
    Like you say though, the fun comes from adding your own tweaks and modifications.
    I love your fabric choices too 👍😊🙏

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  2. Thank you for this great info. That wonky bit of zip at the end is like spinach between your teeth. Can’t wait to try this and, yep, the seam at fly edge does add the stability that is essential in a proper trouser. Great red trousers.

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  3. Thanks for this intro to French Flies. I believe the point is that it stops drag on the top of the zip. But I love the idea of sewing the luxury we cannot afford💕 I’m the same keep winging and keep breathing and double checking and somehow it works. I’m with you on the flimsy ness of the front edge though. I like the instructions on my Vogue menswear patterns for a scr

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