Wednesday, March 19, 2008

Seam Finishes

Seam finishes include any method of sewing or trimming seam edges to prevent raveling. You need seam finishes on woven fabrics, usually it is not necessary on most knitted fabrics. These finishes are added after seams are stitched and pressed. The method used depends on the fabric type and the reason for finishing the seams.

Machine Zigzag Seam Finish
This is a fast and easy method for finishing fabrics that ravel. Set the zigzag setting for medium width and length. For loosely woven or heavy fabrics use a wide stitch.
Zigzag along the edge of each seam allowance.

Pinked Seam Finish
Most firmly woven fabrics can be trimmed with pinking shears. Pinking doesn't prevent raveling entirely. For more protection, stitch 1/4" from each edge before pinking. Press seam open.

Hemmed Seam Finish
This method forms a narrow, single-fold hem along the edges of the seam allowances. Also called "clean finish" or "turned and stitched" seam finish. Use on lightweight to medium-weight fabrics. Attractive on unlined jackets. Turn the edges of the seam allowances under 1/4" and press. Stitch close to the folded edge.

How to Sew a Lapped Seam

One piece is lapped over the other and topstitched in place. The lapped seam is often used with natural or synthetic leather and suede.

1. Turn the seam allowance under on the section to be lapped. Press.
For leather and suede, trim away the seam allowance.
2. Lap the folded or trimmed edge over the other piece at the seam line, wrong side to right side.
3. Edgestitch along the folded or trimmed edge.
4. Topstitch again 1/4" from the edge.

How to Sew a Welt Seam

Welt seams are less bulky than flat-felled seams and give a tailored finish on heavier fabrics.

1. Stitch a 5/8" standard seam. Press the seam open.
2. Press both seam allowances to one side.
3. Trim the seam allowance next to the garment to 1/4".
4. Stitch from the outside through the garment and the wider seam allowance. Keep stitching an even distance from the seam line.

How to Sew a Double-Stitched (Reinforced) Seam

This seam works well on curved seams such as armhole or crotch seams. The extra row of stitching gives the seam extra security.

1. Stitch a 5/8" standard seam with the right sides of the fabric together.
2. Stitch again about 1/8" from the seam line in the seam allowance. A narrow zigzag stitch may be used for this second row of stitching.
3. Trim the seam allowances close to the stitching.

How to Sew a Topstitched Seam

Topstitched seams are decorative and give a sporty, tailored, or contrasting finish to a garment or home decorative item. It holds bulky seam allowances flat and emphasizes the seams of a garment.

1. Stitch a 5/8" standard seam. Press seam allowances open.

2. Topstitch along each side of the seam, through both layers of fabric. Keep stitching a straight and equal distance from the seam line.

An alternative method is to press both seam allowances to one side as indicated on the pattern. Topstitch through all three layers of fabric.

How to Sew a Flat-Felled Seam

Flat-felled seams are sturdy and durable. Two rows of stitching show on the outside of the garment.

1. Pin the WRONG sides of the fabric together.
2. Stitch a 5/8" standard seam. Press open.
3. Press both seam allowances to one side.
4. Trim the under-seam allowance to 1/8".
5. Fold in the edge of the upper-seam allowance 1/4". Place it over the trimmed seam allowance. Press.
6. Stitch close to the folded edge through all thicknesses.

How to Sew a French Seam

This seam works well on sheer fabric because no raw edges show on the wrong side. The seam looks like a plain seam on the outside and a narrow tuck on the wrong side. This seam works well on straight seams, but doesn't do well on curved seams.

1. Pin the WRONG sides of the fabric together.
2. Stitch 3/8" from the raw edges. Trim the seam allowances to 1/8". Press seam allowances open.
3. Fold the fabric along the seam line with right sides together. Press.
4. Stitch 1/4" from the folded edge.

This will give you a standard 5/8" seam allowance because 3/8" + 1/4"(2/8") = 5/8".

Monday, March 17, 2008

How to Construct a Standard (Plain) Seam

A plain or standard seam has 5 steps.

1. With right sides of the fabric together, match the cut edges and any notches.

2. Place pins about 5" apart along the seam line. Pins should be at right angles to the seam line and the heads of the pins should be easy to remove as you stitch.

3. Sew along the seam line, 5/8" from the fabric edge.

4. Secure threads at both ends. (Backstitch at the beginning and end.)

5. Press the seam flat, then press the seam open.

Stitch Lengths

The stitch length you use depends on the fabric type and the purpose of the stitching.

Regular (standard) stitching is used for permanent seams and construction details. With most fabrics 10-12 stitches per inch is fine. On our classroom machines the middle dial will be set between 2 and 3 for regular stitch length. For finer fabrics you might need 12-15 stitches per inch, and with heavy fabrics like denim and twill you will have more success with 8-10 stitches per inch.

Basting stitches temporarily hold two or more fabric pieces together until they are permanently stitched. Basting is also used on a single layer of fabric for easing, gathering and marking guidelines. Use the longest machine stitch, usually 6 per inch. On our classroom machines the middle dial is set at 4 for basting.

Reinforcement stitching gives strength to areas that will be trimmed or clipped close to the stitching. Use 15-20 stitches per inch. On classroom machines that is the setting between 1 and two on the middle dial.

Wednesday, March 12, 2008

Steps of the Sewing Routine

I'm having trouble with students that don't follow the routine to sew. Sit up straight, make sure the controller is where it is comfortable for you, and make sure that you are in front of the presser foot before you begin. Always start with the take-up lever up at the top. Always end the same way.

Thread the machine from right to left, making sure that you catch the thread in the thread guides and take-up lever (follow the numbers). Be sure to thread the machine needle from front to back and leave a long thread tail.

To insert the bobbin, make sure the thread is unwinding to the left side, making a P shape. Drop the metal bobbin case onto the bobbin, pull the thread through the slot on the side, then under the flap until it "clicks". Use the lever to help you place the bobbin case into the shuttle of the machine, aligning the peg with the slot at the top. If the bobbin case is placed correctly, it will NOT spin.

Hold the needle thread and turn the handwheel toward you one full turn to raise the bobbin thread to the top side of the machine. Pull both threads toward the back of the machine. Test sew on a scrap first!!!