Denim is a favourite fabric of mine. It wears well, is comfortable to wear and lasts forever, so garments become your old wardrobe standbys. But you want your denim to look like ready-to-wear, not home-made. So assemble your project and notions before starting. The right needle and thread makes all the difference in denim.

An excellent jean pattern from Calvin Klein, available from Vogue Patterns

Denim is a closely woven, twill-weave fabric that comes in a variety of weights. It is woven with indigo yarns in the warp and white yarns in the filling. Heavyweight denim (14-16 oz. Per linear yard) is good for jeans, overalls, and jackets. (If you have ever been to Weight Watchers, you know that denim jeans weigh 2 lbs! Some members remove them before getting weighed.) Medium weight denim, 10 - 12 oz, is good for pants, skirts, tote bags, and jackets. Lightweight denim, 6-8 oz, is a good choice for dresses, full skirts, and shirts.

Butterick 4932 The comfort of a denim jumper

Pre-treatment: Denim is 100% cotton so there will be shrinkage. Some fabrics have what is called progressive shrinkage. Denim is one of them. This means that it continues to shrink through several washes. Therefore it is recommended that you wash and dry your yardage three times before cutting. Don't neglect this step, as you will find that your skirt or pants get shorter every time you wash them. Do use the dryer to do this pre-treatment, as the heat will help get the shrinkage out. You may prefer to line-dry your garment later, as I do, to delay fading. Also, wash your denim garments wrong side out to reduce fading. Hang them on the line inside out as well because the sun will bleach the fabric.

White denim bustier and skirt in dark stretch denim from Vogue pattern 7234

Needle Type: Denim is a woven fabric, so your needle type should be a sharp, rather than a ball-point. The weight (or thickness) of your denim fabric will determine which size needle to use. For medium weight denims, use a 14 needle. For heavier denim, a size 16 will yield better results. For top-stitching and for doing hems, you will probably require a denim or jeans needle. These are made of stronger steel (less breakage problems) and they also have a sharper point so they can penetrate the fabric more easily. The denim needles have a larger eye so it is easier to thread top-stitching thread through them and the thread frays less when rubbing back and forth through the eye.

By the way, did you know that thread passes 60 times through the eye of the needle before it comes to rest in the fabric? A good reason to buy quality thread.

Thread: For thread, good quality cotton or polyester thread is fine. But for top-stitching, you will want to use top-stitching thread in the needle. Keep regular thread in the bobbin, as you don't need that heavy thread on both. I have had some nice results using a triple-stitch and regular thread on denim. The triple stitch is the straight stretch stitch, which goes forward one stitch, then back one, and then forward one again. Everything is stitched three times. Using regular thread, this gives a nice line of top-stitching.

Denim and fashion combined in Butterick 6063

Seams: Denim garments made in factories are assembled with flat-felled seams. These are very difficult to do at home, given the bulk of denim. A welt seam will give the same look on the outside without the difficulty of construction. Sew your seams the usual way, finish the raw edges with the serger or zigzag, press to one side, switch to top-stitching thread in the needle, and top-stitch the seams on the outside to resemble flat-felled seams. You can either stitch every seam twice, once right next to the seam line and a second line ¼" away, or simply stitch once ¼" to 3/8" away from the seamline. It is a little time-consuming but the garment will look more professional and be extremely durable. Of course, you need to know beforehand that it fits, because you don't want to have to unpick all this stitching to alter it later.

The latest in decorated denim from McCalls 2626

Hemming: When hemming denim, you can run into some problems when you turn up the seams and find that you have up to 6 thicknesses of fabric to penetrate. Your sewing machine balks at this. When you reach the bulky seam, it doesn't want to go forward, and once you sit on top of the seam, it wants to run down the hill, skipping stitches. The real problem here is that no sewing machine likes to sew at an angle. It will sew if you can keep the presser foot level. Hence the invention of a notion called the "hump-jumper" or the "jean-a-ma-jig". Before you spend some cash on these notions, see if you can solve the problem yourself. Take a square of the denim fabric and fold it until it matches your seam in thickness. Now, when climbing up the fabric hill, place the wad of fabric (technical term is a shim) behind your presser foot to make it level. When descending, put the shim under the front toe of the presser foot. You should find that you can sew through the bulk more easily. Combine this technique with the correct needle and you won't have a problem.

Denim and ultra-suede make a nice combination. Picture scanned from Burda magazine

One more hint, before taking that hem to the machine, hit it hard a few times with a hammer to smash the fibers. This will break down the bulk and make it a little more manageable. Just don't do this on your dining room table or hardwood floor. A nice piece of plywood comes in handy for this. So now you can add a hammer to your sewing notions!

Bar-tacks: Almost all denim garments have bar-tacks at strategic points, such as the top of patch pockets, at the curve on the fly top-stitching, on the belt loops. If you have a machine with a bar-tack stitch, lucky you. If you don't, set your machine for a narrow zigzag, about 2, and a very short stitch length. Sew for ¼" and reverse to reinforce. Make a sample first to see how long and how wide you like your bar-tacks. Or apply metal studs, according to the instructions provided with the package.

Authentic jean styling on plus-size patterns from Butterick Patterns

Hems: Top-stitched hems on denim garments tend to curl up to the outside. If you want a narrow top-stitched hem, this is almost unavoidable. But if you widen your hem just a tad to about ½", you may be able to prevent this. The hem just needs a little more weight to it to prevent the curling. To avoid the problem altogether, make your hem about 1" wide and double top-stitch at the top of the hem. Don't use a twin needle to do the top-stitching because you don't want a zigzag stitch to show when your hem flips up. To top-stitch two perfectly straight lines, stitch first one line, then simply move your needle position to the left or right to make the second line. Or run the edge of your presser foot along the first line of stitching when you do the second.

Tip: Claire Shaeffer, in her book Fabric Sewing Guide, recommends fusing a piece of Wonder Under to the hem allowance, then folding an fusing the hem in place before top-stitching.