Basic Construction--Sewing Plain Seams

A seam is a line of stitching that holds two layers of fabric together. A plain seam is the standard seam used for most sewing. It is 5/8 inch (1.5 cm) deep and stitched with the standard stitch length for your fabric. Patterns are designed with standard seams unless stated otherwise.


For best results in stitching seams, always follow these steps:

1. Stay-stitch any bias or curved areas ½” (1.3 cm) from the cut edge.

2. Pin-baste the fabric layers along the seam line, with right sides together. Match fabric ends and notches; then pin. To keep the fabric edges even, place additional pins 5 inches (15 cm) apart. Insert pins at a right angle to the stitching line, with heads toward the seam allowance.

3. Raise the needle and take-up lever to their highest point by turning the hand wheel. Be sure thread ends are behind the presser foot to prevent the thread from pulling out or jamming when you start to stitch.

4. Position the fabric under the needle. Line up the fabric edge with the 5/8-inch (1.5-cm) marking on the right side of the needle plate.

Place the fabric about ½-inch (1.3 cm) in from the end for backstitching. Turn the hand wheel to lower the needle into the fabric. Lower the presser foot.

5. Backstitch for ½” (1.3 cm) to the beginning of the seam line.

6. Stitch forward slowly and evenly to the end of the seam. Remove pins as you stitch.

7. Backstitch ½” (1.3 cm) to secure seam.

8. Remove the fabric by turning the hand wheel to raise the take-up lever and needle to their highest position. Lift the presser foot. Slide the fabric toward the back of the machine.

9. Clip threads at seam beginning and end.

10. Finish the seam edges if necessary.

11. Press the seam open.

Turning a Corner

To turn a corner in the middle of a seam, stitch to within 5/8" (1.5 cm) of the corner and stop with the needle in the fabric. Lift the presser foot and turn the fabric on the needle. Lower the presser foot and continue stitching in the new direction.

Turning a Corner fgr 1

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When sewing with a conventional sewing machine, remove each pin just before it reaches the presser foot. A needle can bend or break if it hits a pin. Never place pins on the underside of the fabric. They can catch in the feed dog and break the machine needle or tear the fabric.

Never sew over pins with a serger. Pins can damage the knives and needle, and pin fragments could fly into your eyes or face. Instead, place pins at least 1 inch (2.5 cm) from the edge, parallel to the stitching line, or remove each pin before it reaches the knives.

To keep pins off the floor, place them in a pincushion as you stitch. Never place pins in your mouth or clothes.

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--- Serging Techniques ---

Plain Seams

1. Pin the seam. Position the fabric in front of the presser foot. Match the stitching line on the fabric to the appropriate mark on the seam guide.

2. Serge a 4- to 5-inch (10- to 12.5-cm) thread chain. Then gently feed the fabric under the presser foot.

3. Serge off the fabric for 5 to 6 inches (12.5 to 15 cm). Bring the thread chain around to the front so the knife can cut it.

4. Secure the thread ends. Run your fingers along the thread chain to smooth it out. Tie the thread in a loose loop knot. Insert a pin through the center of the loop so the pin tip is next to the fabric edge. Pull the thread chain until the loop tightens into a knot at the pin tip.

  • Remove the pin and clip the thread tails.
  • Seam line Seam allowance is 1/4".
  • Cutting line Trimmed fabric is 3/8".

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Turning a Sharp Point

To turn a sharp point, such as the point of a collar, take one or two diagonal stitches across the corner. The extra stitch makes a thinner, neater corner when the point is turned to the right side. See Fig. 2.

Turning a Sharp Point 2

To do this, stitch to the corner and leave the needle in the fabric. Raise the presser foot and turn the fabric diagonally. Lower the presser foot and make one or two stitches by turning the hand wheel. Leave the needle in the fabric, raise the presser foot, and turn the fabric to complete the corner. Lower the presser foot and continue stitching.


To reinforce a sharp corner or point, such as a V-neckline or placket, use reinforcement stitches. Stitch again for about 1” (2.5 cm) on each side of the point. This helps prevent fabric yarns from pulling out of the seam after the fabric is trimmed and turned. See Fig. 3.

Reinforcing a Point 3

== Wiki Sewing ==

Knot the Thread

The knot on hand-sewing thread should be at the end of the thread without a tail of thread beyond the knot. The size of the knot depends on the weave and weight of the fabric you're sewing. A heavy, loosely woven tweed fabric will need a large knot, while a thin, silky fabric will require a small, fine knot.

1. Place the end of the thread on the palm side of your index finger, with the end of the thread toward your body. Hold it in place with your thumb.

2. Bring the thread under your index finger, around your finger until it will slip under your thumb.

3. Roll the thread between your thumb and index finger, while rolling across the bottom of your thumb.

4. Allow the end of your middle finger to help hold the thread between the bottom of your middle finger and the top of your index finger. Pull the thread with your right hand as you use your thumbnail and index finger to snug the knot down to the end of the thread.

TIP --- A Large Knot:

You can make a large knot by rolling the thread more on your finger or by repeating the entire procedure and encapsulating the first knot.

<<== Wiki Sewing cont. ==>>


Some seams may need special treatment to reduce bulk in the seam allowance. Enclosed seams, such as those in necklines, collars, and cuffs, should lie flat and smooth. Curved seams and corners also need special treatment. You can reduce the bulk of a seam by trimming, grading, clipping, and notching.


The seam allowances of enclosed seams should be trimmed to an even width, usually 1/4 inch (6 mm). See Fig. 4.

The corner of a seam allowance should be trimmed diagonally to remove extra thickness when the corner is turned. See Fig. 5. If the corner is very pointed, make an additional diagonal cut on each side of the point, trimming to 1/8-inch (3 mm). See Fig. 6.

Curved seams, such as the lower part of an armhole and the center back seam of pants are usually trimmed.

These areas can be reinforced with two rows of stitching ¼” (6 mm) apart and then trimmed close to the second row of stitching. See Fig. 7.

4 Trimming Seam Allowance; 5. Trimming Diagonally; 6. Making Extra Cuts; 7. Trimming Curved Seam


Grading means to trim each layer of the seam allowance to a different width to reduce bulk.

Enclosed seams in heavier fabrics should be grad ed. Seams with three layers of fabric, such as a collar stitched to a neckline, should also be graded.

Always grade a seam so that the widest seam allowance is next to the outside of the garment.

This reduces press marks on the right side. To grade, trim the seam allowances in half. Then trim the seam allowance toward the inside of the garment in half again. See Fig. 8. For three layers, trim each one slightly narrower.

Grading a Seam 8


On a curved seam, the seam allowances should be clipped to allow the curve to lie flat when pressed. Clipping means making tiny clips, or snips, in the seam allowance every 1/4 to 1/2 inch (6 to 13 mm). Using the point of the scissors, clip to within 1/8 inch (3 mm) of the seam line or up to the stay-stitching line. The sharper the curve, the closer together the clips should be made.

Clipping is done after the seam is trimmed or graded. See Fig. 9.

Clipping a Curved Seam 9

Sometimes an inward curve or corner must be clipped before stitching the seam. Stitch a row of reinforcement stitches just inside the seam line in the seam allowance. Clip up to the reinforcement stitches to allow the fabric to lie flat for stitching the seam.


Some curved seams have too much fabric in the seam allowance after being trimmed or graded. The extra fabric forms ripples and doesn't allow the seam to lie flat. These are usually out ward curves that are turned and pressed to form an inward curve, as on the outer edge of a collar.

Notching means cutting out tiny wedge shaped pieces of fabric from the seam allowances.

See Fig. 10. Notch no closer than 1/8” (3 mm) to the seam line. When the seam is turned and pressed, the sides of the notches should meet.

1. Press seam flat. 2. Press seam open.

Pressing a Seam 11


Seams should be pressed after they are stitched and before they are crossed by another seam.

Check your pattern guide sheet to see whether the seam is to be pressed open or to one side.

First, press all seams flat to blend in the stitches. Then open the seam allowances and press again. If necessary, press both seam allowances to one side. Curved seams should be pressed over a tailor's ham. See Fig. 11.

Enclosed seams in a collar or cuff should be pressed open before turning.

Use a point presser or sleeve board and press with the tip of an iron. Then turn the fabric to the right side and lay flat on an ironing board with the underside up.

Roll edges in just until the seam shows and press lightly. This helps prevent the underside or facing from showing along the edge. See Fig. 12.

Notching a Curved Seam 10

Pressing Enclosed Seams 12

1. Press enclosed seam open before turning.

2. Roll seam to underside and press.


A seam finish is any method of sewing or trimming seam edges to prevent raveling. A seam finish is needed on woven fabrics, but not on most knitted fabrics. After the seams of a garment are stitched and pressed, a seam finish can be added.

Seam Finishing Methods

When finishing a seam, the method to use depends on the type of fabric and the reason for finishing the seams. Zigzag stitching and serging are the easiest and quickest methods.

• Machine zigzag 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. See Fig. 13.

• Pinked finishes. Most firmly woven fabrics can be trimmed with pinking shears. See Fig.

14. Pinking doesn't prevent raveling entirely. For more protection, stitch ¼” (6 mm) from each edge before pinking. Press the seam open.

• Hand-overcast finish. Although very time consuming, this method is sometimes used for sheer or delicate fabrics. Make overcast stitches by hand over the edge of the seam allowances. See Fig. 15.

• Hemmed finishes. This method forms a narrow, single-fold hem along the edges of the seam allowances. It is also called a clean finish or a turned-and-stitched finish. Use this method on lightweight to medium-weight fabrics. The finish is attractive on unlined jackets.

Turn the edges under 1/4 inch (6 mm) and press. Stitch close to the folded edge. See Fig. 16.

Machine Hemmed Finish 16; Zigzag Finish 13; Pinked Finish 14; Hand-Overcast Finish 15

-- Serging Techniques --

Seam Finishes: To finish a conventional seam, use a two thread or three-thread serger stitch. As you serge, the knife should skim the edge of the fabric so nothing is trimmed from the seam allowance except a few loose threads. Finish the edges of the fabric before stitching the seam.

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Saturday, 2012-04-07 14:54