I found some unexpected motivation yesterday since I discovered that the pair I plan to copy has a hole in the butt. Gah! And I wore them to work last week without noticing it. Anyhow, I have gotten started now and here comes the first installment - the jean zipper. First a word of warning tough. The techniques in the tutorials will make the jeans look very similar to store bought ones, however these more industrial methods makes fitting the jeans as you sew hard or next to impossible. So assert things like fit before you start. Preferable by sewing a muslin or adjusting the pattern using your favorite pair of jeans as a guide.
The first step after cutting out the pieces are the zipper application. Most jeans patterns that I have seen use a zipper method that has very little to do with a proper jeans fly. Like Anita for instance, which is the Burdastyle pattern that I'm using. I have picked up the basis of this method from the books Sew U by Wendy Mullen and The practical guide to pattern making for menswear and then tweaked it a bit.
Using the awl again make another hole higher up where the crotch seam will be.
Now clip where the outer zipper top stitching will end, if you plan to make two seams clip twice. Also clip where the crotch seam will end.
Mark the outer zipper stitching line on left piece, using tracing paper or your preferred tracing method. The right front piece is traditionally used for menswear, if you care to make such differentiation.
Now to the piece that are not always included in jeans patterns - the zipper shield. It is however easy to draft your own. The finished side length should the same as the flap and the finished width the should be the same as the width of the flap.
Just add seam allowance (1/4 inches/0,6 cm). The middle part should about 2/5 inch (1 cm) shorter than the sides of the shield. If you feel confused, just examine a pair of jeans and see how the shield is positioned and the shape of it.
Before you continue, interface the back of the left flap and the area that should be topstitched. Then serge the crotch seam on both front pieces plus the side of the left flap.
Then sew the front crotch seams together, ending where the little hole is. Yes you don't sew one leg at a time when making jeans. Hence the fitting difficulties.
Then, using a loose basting stitch, sew the seam all the way to the top. This is where the clipping and the second hole comes in handy.
Then trim away the right flap so that only 3/4 inches/1,8 cm remains . I think a proper industrial jeans pattern probably has two front pieces, one with the wide flap and one with the narrow, but since most commercial jeans patterns don't, I'll use this method instead.
Place the zipper face down on the right (and trimmed) flap. I use a little craft glue to keep it in place, hence the white spots. You can baste too, but do not use pins, it will distort the fabric.
Stitch the zipper into place.
Then sew the shield.
And turn and press. It doesn't have to look perfect.
Place the shield on top of the flaps. The longer side should be on the trimmed right flap. Attach the shield to the right flap, sewing a narrow seam (again a little water soluble glue is great for keeping it in place when sewing).
Open up the shield so that the zipper faces up. Stitch a narrow seam to keep the fold in place. Just look at your jeans to see how this work if you feel unsure.
Now turn the zipper again so that it faces the trimmed right flap. The front side of the zipper should rest against the flap. Stitch the zipper so that it attaches to the right flap.
Phew, almost there. Only the topstitching remains. Fold the shield to the right, do not sew over the shield! Topstitch, ending just above the curve.
Then fold over the the shield. Here you can use a pin to keep it in place.
Sew two rows from the other direction, over the shield.
Using a tight zigzag, secure the seams. And if you like you can do the same over the crotch seam (I used navy thread there, so I don't think it shows well).
ETA: I forgot to mention that there is usually an edgestitch on the jeans fly too. I just didn't add one because the pants I am copying didn't have one. Do the edgestitch after you have basted the crotch seam. Also my way of topstitching the fly is just one of many ways of doing it.
And this how the shield looks like. Mine is a bit too wide, because I had originally planned to make the zipper stitching wider than what the Burdastyle pattern calls for. But I never got around to it. There is definitely a learning curve for this method, but the end result will look pretty professional even after the first try. Hope you will find this tutorial helpful!
For a slightly different take, but with the same principles see Debbie Cook's tutorial for sewing a jeans fly.
Using an awl or any other sharp object, punch a hole where the crotch seam should end. Punch just outside the seam allowance. This method is much quicker than a pen or tracing paper.