Kate’s Tips and Tricks for Sewing with Denim

I’ve just started sewing a new pair of Cashmerette Ames jeans using our Repreve Stretch Denim in White, and I’m over the moon about it! I’ve always wanted a pair of white jeans, and summer is the perfect time to make my white denim dream a reality!

I’ll be sharing many tips for sewing with beefy fabrics like denim as I make progress on my Ames Jeans via Facebook Live (every Wednesday at 3:00 pm Mountain Time), but, to start, I’ve compiled a few essential tips that will help prepare you (and me!) for the coming Ames journey. You can watch my companion Facebook Live video by clicking here.

Many (most?) sewing machines are strong enough to sew through denim especially with the correct needle, stitch-length, and tension. Small, entry-level machines, might not be able to power over the denim, but the tricks in this blog post will help. 

• Depending on the thickness of the denim, I use a straight-stitch length between 3.0 mm and 4.0 mm. I also increase the tension on my machine to 4.6 (up from 4.0 for lightweight woven fabrics). If my denim has spandex in it, I use a stretch stitch, such as a narrow zigzag. I like a 1.5 mm wide by 2.5 mm long zigzag. Sewing stretch denim with a straight stitch can lead to popped seams (ask me how I know!).
• A new denim needle, either size 90 or size 100, is vital. Denim needles will penetrate the thick fabric with minimal deflection and are less likely to break.  If you’re using thick topstitching thread, you’ll want a size 100 needle. It has a bigger eye than the size 90.
• When sewing with non-stretch denim, I like to use thick thread (along with a size 100 needle) for the topstitching. I love the “store-bought” look that comes from using the same thread as jeans-making factories. However, if I’m sewing with stretch denim, or my machine is not cooperating with the thick topstitching thread, I use a triple stitch with regular thread. The triple stitch is officially a stretch stitch, so it will stretch with my garment. Regardless of my top thread, I use regular (50 wt.) thread in my bobbin, because topstitching thread is too thick for my bobbins to handle.
• I use a regular foot or a straight-stitch foot for jeans’ seams, and an edge-stitching foot for most of the topstitching. 

When pinning a few layers of denim, I like to use our Merchant and Mills Glass-Head pins because they are sharp, short, and stout. They don’t bend under pressure. Since they are glass-head, I can iron on them. No pin can withstand the thickness of nine layers of denim, however, and that’s how many there usually are at the side-seam jean hem. So, when I want to hold more than two or three layers of denim, I use Wonder Clips.

One of the biggest challenges in sewing with denim is getting over the “humps” created by multiple layers of fabric. Bulges are difficult to get over because they force the foot to be diagonal, which means it’s not engaged with the feed dogs below the fabric. We have a great tool, called the Big Jig, which allows me to lift the foot so it remains parallel to the feed dogs as I approach the hump, and then the Big Jig allows me to keep the foot parallel to the feed dogs as I come down the other side of the hump. I use the Big Jig every time I topstitch over intersecting denim seams.

In addition to using a Big Jig, I have three tricks for hemming jeans. First, I interface the edge of the fabric with half-inch woven stay tape, which keeps the hem from popping up after washing. Second, I hold the hem in firmly in place with double-sided stay tape. And, third, I mark where I want to sew the hem on the right side of the fabric with a fabric pen. I always like to “topstitch from the top”. Which is especially important when I have a different thread in the bobbin. 

And with that, you’re one step closer to becoming a jean-ius! Thanks for reading, and let me know if you have questions to ask or tips to contribute for sewing with denim! You can email, call, or comment on Facebook. No question is too small.

Happy Sewing!

-Kate