a “probably different than you’ve seen before” flat-felled seam tutorial

Many months ago, I was deep internet researching jeans-related construction, and came across a forum convo about flat-felled seams. I can’t remember exactly where this was posted (pattern review maybe?) but I tucked that info away in mah brain and pretty much forgot about it until now. I pulled out some denim for a pair of jean shorts and decided to do some testing on scraps. I was pretty excited about how my seams came out (as were you!) that I immediately tried another sample and snapped pics. Like I said, I didn’t come by this method independently, so if you’ve seen this discussed elsewhere, give me a holler so I can give credit where credit is due. [*UPDATE* Found it! It was a pattern review thread… I can’t seem to link directly to the convo, but it’s under “sewing techniques and tips>how to sew RTW style flat felled jeans seam.”]

There are two things that have always bothered me about the center back crotch seam on jeans (now there’s something only someone who sews might say…). First, the way things are usually constructed, the seam allowances are pressed to one side of the seam line. This means that the top stitching is not centered, and the pockets are not equidistant from the top stitching. You can space the back pockets differently on each side to offer a little more symmetry, but ultimately I would prefer a centered seam. The second thing that annoys me is that the original stitching line can end up looking a little bit strained. Even though the seam is perfectly secure from all the lines of stitching, sometimes you end up pulling on the original seam and you’ll see the lighter part of the denim showing through. Hard to explain that one, but if you’ve ever noticed this, you know what I’m getting at.

METHOD 1 | 3/8″ SA

I’m going to show two slightly different methods. The first method requires a 3/8″ SA, and is particularly useful on thicker fabrics because the final seam ends up with only 3 layers of fabric. (Click on the photos to enlarge)

Take the fabrics you will be joining, abut them, and sew a wide zig zag stitch to join them. Do not overlap the fabric. It doesn’t matter what thread you use, because this stitching will be hidden at the end.

This part gets difficult to explain, so bear with me and when in doubt, refer to the photos. Press the fabric just to one size of the zig zag stitching (about 3/16″ from the abutted edge), then turn to the other side and do the same. If you look at a cross section, your fabric will form a “Z”. The abutted seams are on the inside of the folds and completely covered.

Top stitch from the right side, then make a second pass, which will just catch the folded edge on the wrong side. I like to use my blind hem foot as a guide, and I found that the folded ridge on the under side is lumpy enough that the foot can follow it for the second pass. This eliminates any guesswork or need to sew from the wrong side. Given that most machines have difficulty producing a nice stitch with top stitching thread in the bobbin, this is most useful!

At the begining I had marked the 3/8″ SA, and you can see that my marking is neatly centered. Also, you will note that the finished seam has three layers of fabric, making it perfect for thicker fabrics.

METHOD 2 | 1/2″ SA

The second method is essentially the same as the first, but it ends up being a little bulkier, and requires a 1/2″ SA.

Start by pressing one of the SA’s to the right side by 1/4″, and the other SA to the wrong side by 1/4″. Open it up, and overlap the pressed SA’s, using the pressed line as a guide.

Once overlapped, run a line of basting stitches down the center. Again, thread doesn’t matter, the stitching will be hidden in the final seam.

Since the seams have already been pressed, top stitch as before: first at the outer folded edge, then again along the inside folded edge. Since the fabrics are overlapped instead of abutted, you end up with 4 layers of fabric in the seam.

You can see from my chalked marking that I got off ever so slightly, but this is a sample and a super unprofessional blog, so I didn’t feel compelled to re-do it.

It occurs to me that you could also mark 1/4″ on one SA, overlap the other fabric, baste, then press the seams after basting. Give it a go on some scraps and see what works for you.

Before you ask, I did try the first method (though not the second) on a curved edge in order to simulate the back crotch seam of jeans. I found that I had absolutely no issues with the curve. If anything it was easier because all the top stitching was closer to the edge of the fabric. When you press a curved edge to one side, the edge of the fabric is shorter than the line where you would be top stitching. You can clip the curve if you are faux flat-felling, but the seam will be inherently weaker. That’s not to say you’re in danger of splitting your jeans, but if there’s a better way I’m all for it. I hope you give this a try!

—lisa g.

my first jean-like pants

i’ve made pants and shorts before, so i’m pretty comfortable with the whole process. still, i’ve put off making any actual jeans. but as with many of my sewing adventures, i try new stuff out on my kids first. i picked up this green stretch twill for pretty cheap and was dying to try out the famed jalie #2908. if you don’t know jalie patterns, they specialize in all things stretchy and active, and each pattern comes in approximately 5,987,423 sizes. since i’ve been into tracing patterns lately, i was okay with this.

i set off tracing each piece suuuuuupeeeerrrrr carefully. the pattern has 3/8″ SA, so there isn’t much room for error. overall the directions are very good and i didn’t need many changes. she wanted a skinny pant so i narrowed the legs in for a custom fit. hey, every kid needs custom fit pants, amiright? i started out by cutting a straight leg so i could taper as needed. i ended up taking in the seams by about 3/8″ below the hip, and 5/8″ from the knee down.

other changes were pretty minor. i added one of those little change pocket things, which i stitched onto the facing before assembling the front pockets. i made up a separate fly facing instead of the folded in variety, and cut a separate inner and outer waistband. i feel both of these are sturdier when cut separate instead of just folded. the pattern has a seam at the CB of the waistband, i’m not sure if this is just to save fabric or what. the waistband is a straight rectangle, so if/when i make her another pair i’ll eliminate the back seam.

i topstitched throughout to mimic RTW and even added a regular jeans hammer it in shank button. i don’t have pics of the shank button because initially i had sewn on a regular button because she was so eager to wear them and i hadn’t bought a jeans button yet. the shank button makes all the difference in the world for that real look. plus you get to hammer stuff. which is fun. next time i think i’ll try rivets too.

she wanted a lightning bolt design for the back pocket because she is a huge fan of the “percy jackson and the olympians” series (one is entitled: “the lightning thief”), not to mention harry potter.

i thought i would give you a comparison between these and a RTW pair. she usually wears an 8 slim, so i decided to make a size 7. in retrospect, i should have cut the waistband and length in size 8, then slimmed down to a 7. they’re long enough for her, but an extra inch wouldn’t have hurt!

so here they are next to a 7 slim skinny jean from old navy. it looks like the sizing would be very consistent with RTW, though the waist may be a tad snug by comparison.

the only thing that really bugs me is the giant back pocket. see how much larger it is than the ON jean? HUGE! i didn’t even think about this before stitching it on. i will definitely make a smaller pocket next time.

after this i feel pretty confident to make some jean-like pants of my own. i’ll want to alter some of the SA’s for a proper flat fell in places, but overall this is a really nice pattern. call me crazy, but i’ve been oogling over all the floral/patterned skinny jeans for spring. it’s hard to track down floral stretch twill in a pant weight, but i finally found some online at mood… if i feel daring enough, i’m tempted to make my own!

—lisa g.