Sewing With Denim

Selecting, preparing, interfacing and lining denim, denim sewing techniques
Fabric and Pattern Selection
Fabric Preparation
Interfacing
Lining
Sewing Techniques
Add Interest to Denims

Denim is popular all over the world. Jeans made of denim are worn by millions of people. The term denim is derived from the French "serge de Nimes," a twilled fabric made in Nimes, France. It was used as "sail" cloth for ships crossing the Atlantic Ocean.

Traditionally denim was used for working garments and is part of the American tradition. Now it can be found in everything from work clothing to evening wear. We see drip-dry denim, printed denim and knitted fabric made to look like denim -- which, in the true sense, is not denim at all.

Traditional denim is 100 percent cotton with indigo blue warp (lengthwise) yarns and white weft (crosswise) yarns. This color combination usually is made with a left-handed twill construction creating the familiar diagonal lines. The twill weave helps create the strength and durability of the fabric.

Many denim fabrics are 50 percent cotton, 50 percent polyester or other fiber combinations. Cotton/Lycra blends offer 14-17 percent stretch for a comfortable fit on close-fitting garments. The cotton/polyester blends give the best of both fibers -- strong wear and comfort, plus limited shrinkage and wrinkling.

When you buy denim be sure to check the label for fiber content and care instructions. Fabrics which contain polyester generally need different care than those which are 100 percent cotton.

Fabric and Pattern Selection

Denim comes in a variety of weights. It ranges from the traditional 12 oz. and 14 oz. per yard denims used to make jeans and jackets, to a lightweight 6 oz. version that is soft, drapes well and can be fashioned into skirts and blouses. Always be sure to choose the proper weight for each garment.

Since denim is versatile, pattern selection is almost unlimited. Drape the fabric over your hand to see if it will be right for the pattern lines you have chosen.

Denim has a twill weave and if the twill is prominent, avoid patterns which are "not suitable for obvious diagonal fabrics." When purchasing denim, use the "with nap" yardage requirement.

Fabric Preparation

The nature of traditional 100 percent cotton denim is to shrink after washing, fade after wearing and stretch as it gets older. Preshrink denim before sewing to prevent additional shrinkage. Preshrinking removes sizing and other chemical residues that can cause skipped stitches, and it reduces crocking, which is the rubbing off of surface dye onto other fabrics or skin. Read the care label at the end of the bolt for manufacturer's instructions.

Check for the Sanforized® label on the end of a bolt when buying denim. The Sanforized® treatment assures that shrinkage will not exceed one percent in either the lengthwise or crosswise direction.

Before washing, serge or zigzag the cut edges of the denim to prevent them from raveling.

Interfacing

Select suitable interfacing to stabilize, shape or add body to garment sections. Always test the interfacing on scraps of fabric before using it on garment pieces.

Areas to be interfaced include waistbands, pocket flaps, buttonhole areas, collars and cuffs. Use the stability in the lengthwise direction of the interfacing for waistbands and buttonhole areas. If the denim is firm and stable, it may be necessary to interface only the buttonhole area.

Lining

Denim garments usually are not lined. However, a lining may be used to provide comfort, preserve shape, or provide a neat inside appearance.

To eliminate bulk in facings pockets and yokes, cut the facing from lining fabric instead of denim.

Sewing Techniques

Handle denim as you would any other firmly woven fabric. For heavy-woven denims use a larger sewing machine needle (size 16 or 100) and a longer stitch length (10 stitches per inch). For lighter-weight denims use a smaller needle size, 11 or 14 (70 or 80), and 12 stitches per inch. Adjust the presser foot pressure so the fabric feeds evenly. Test the sewing machine stitching on a double thickness of fabric before starting to sew.

Seams

Regular seams may be used on denim. To prevent the seam from raveling, choose a suitable seam finish. Machine-finished edges include the straight stitch with pinked edge, zigzag, multi-stitch zigzag and the serged edge. 

A bound edge is recommended for unlined jackets. The edge of each seam allowance is enclosed in double fold bias tape. Place the tape so the narrower half is on top. Edge stitch it in place.

The flat-felled seam is the most often used with denim. It is durable and gives a nice, clean finish to unlined jackets and jeans. Most seams can be finished with this method, but the armhole seam can be flat-felled only if it has a shallow sleeve cap such as a shirt sleeve. To make a flat-felled seam:trim seam allowance

Welt seams work well for heavy-weight denim and have nearly the same appearance as the flat-felled seam. To make a welt seam:

For a double welt:

Fringed seams can be used for sides of pants and yokes. To make a fringed seam:

Inside out seam is a decorative type seam. To make this seam:

Serged seams may be on the inside or outside of the garment. Use matching or contrasting thread on an outside serged seam. Topstitch the serged seam down close to the serging.

Topstitching

Topstitching your denims can add a lot of fashion appeal, but only if it is done well. Topstitch in single or multiple rows with heavy contrasting thread, such as buttonhole twist. On the bobbin use regular weight thread and loosen the top tension to accommodate the heavier thread. Be sure to test stitch and adjust tensions to make a balanced stitch.

If heavy topstitching thread is not available, try using two strands of regular weight thread, threading them through the sewing machine needle. Increase the stitch length, allowing the threads to float on top of the fabric.

Try using a denim needle especially designed for topstitching. This needle has a longer, sharper point that will penetrate the densely woven yarns of denim, and a larger eye for using heavier sewing threads. These features alleviate thread fraying and shredding by making a larger hole in the fabric for the thread to pass through.

Fly Front Zipper Application

The fly front zipper mainly used on menswear has become a popular fashion detail on girls' and women's garments, too.

On menswear the fly front laps left over right. On women's ready-to-wear the direction of the overlap varies with garment manufacturers. Instructions given here are for a finished zipper lapping left over right. The instructions easily can be adapted for right over left lap.

Patch Pockets

Patch pockets often are used on denim clothing. The pockets can be round, square or triangular in shape. Finish the top of pockets by making a narrow 3/8" to 1/2" hem.

To make a smooth, round pocket, sew an easing stitch on the seam allowance of the rounded area. Pulling the easing threads turns the seam allowance under. Notch out excess fullness from curved seam allowance. Press the pocket. The cardboard idea described here may be used to shape pockets as ease threads are pulled.

First, cut a cardboard pattern the size of the finished pocket. Then, with the cardboard on the wrong side, press the hem and seam allowance over it. (Figure 5). Notch out excess fullness.

creating rounded pocket

A square pocket is made with mitered corners. To miter a square corner, turn seam allowances inside and press. Press corners diagonally through creases. Trim corners 1/8" from diagonal creases. Fold corners with edges inside on creases. (Figure 6.)

creating square pocket

For a triangular-shaped pocket, cut a cardboard pattern the size of the finished pocket without seam allowances. Place the cardboard on the wrong side of the pocket fabric, allowing the seam allowances to extend beyond the cardboard. Press the seam allowances over the cardboard pattern. Notch out excess fullness.

Machine stitch fancy designs to your pockets. Do not copy the designs from big name jean companies. Those designs are their trademarks and copying them is an infringement upon their rights. Design your own fancy pockets. Here are some ideas you can copy. (Figure 7.)

decorated pockets

Baste the pocket to the garment using pins, thread, glue stick or stitch witchery. Topstitch with one or two rows along the edges. Reinforce the top corners by sewing a triangle, using a tight zigzag stitch or double-stitching.

Hems

Machine-stitched hems are the easiest to do and are recommended for denim garments. Usually a narrow, machine-stitched hem works well. After the hemline is marked, trim the hem allowance to 3/4". Stitch 1/4" to 3/8" from the edge; turn hem under on the stitching line. Turn and press. Topstitch using one or two rows of straight or decorative stitching.

A fringed hem is easy to do, but it is time-consuming. Mark the hemline, then cut along that line. Stitch 5/8" from the cut edge. Stitch a second row 1/4" above the first row. Carefully remove threads below the lower stitching line, clipping any threads that are caught in the stitching.

Add Interest to Denims

Use a compatible contrasting print to face hems, collars, front bands and pockets.

Select decorative zippers, colorful buttons and decorative gripper snappers.

Trim with studs, appliqués, decorative braid, rhinestones, embroidery stitches, cross stitching and trim such as piping, lace or eyelet.

Denim garments have made their way into the wardrobes of young, old, male and female, and denim's end uses have been multiplied many times over. It is worn for weekend activities, to the office and for special occasions. Wherever it is worn, it has made its way into the fashion picture.