May Martin’s Sewing Bible: 40 years of tips and tricks. May Martin

      The thread is taken through tension discs on the upper part of your machine. When the machine foot is up, there is no tension on the thread. Put the foot down and the tension discs hold on and control the upper thread. If you have a tension dial on your machine, the middle three numbers will have a line against them, the middle number indicating the optimum level of tension. Alternatively, your machine may give a digital readout of 0–10, in which 0 indicates no tension and 10 the maximum level. Increase the number and the tension discs will hold on more tightly. Decrease the number and the thread will be held more loosely.

      Lower thread tension

      Refer to the trouble-shooting section before attempting an adjustment to bobbin tension. The tension is controlled by a tiny screw on the bobbin case and I strongly recommend you seek guidance before altering it.

      Balancing tension

      If the top thread is too tight or the bottom thread too loose, the bottom thread will show on the top of the seam.

      If the top tension is too loose or the bottom tension is too tight, the upper thread will show on the underside of the seam.

Troubleshooting

      If you are not sure what is happening to your stitching, thread the top and bottom of your machine with exactly the same type of thread but in contrasting colours and you will be able to see the stitch clearly and have a better idea of how to adjust it. Before you start altering the settings, however, check the following:

       Make sure your upper and lower threading is correct – refer to your sewing machine manual for advice.

       Is the needle damaged? You may need to replace it.

       Are there any fibres or bits of thread caught in the tension disc? Fold a piece of fabric in half and insert it in the tension discs and move up and down.

       Do the top and bobbin threads come from the same reel? Ideally, both threads should be from the same reel to ensure that the tension is evenly balanced.

       The screw that controls the bottom tension may vibrate loose while working on some machines. The tension can be tightened by turning the screw on the bobbin case in a clockwise direction.

      Machine Stitches

      Straight Stitch & Zigzag Stitch

      The two main types of machine stitch are straight or running stitch and zigzag stitch. A dial or button on your machine regulates the length of the straight stitches; the higher the number the larger the stitch. Most stitching should be sewn in the middle of the range. Another dial or button adjusts the width of the zigzag stitches; again, the higher the number the greater the width of the stitch.

      If you choose a straight-stitch setting, the stitch-width dial or button for zigzag stitching can move your needle over, enabling you to work rows of stitching in different positions. With these two ways of setting stitches on your machine, you can change the length and width of any stitch.

      Application of Straight Stitch

      A medium-size straight stitch is an essential for most construction techniques and decorative topstitching.

      Staystitching

      This is a row of machine stitching sewn inside the seam line to prevent stretching. It is usually worked on curves to support the grain – for example, along the edge of a neckline. It is worked on a single layer of fabric as soon as the paper pattern is removed.

      Understitching

      A row of straight machine stitching worked on the right side of the fabric close to the seam line on the facing edge of a garment. The seam allowance is trimmed, layered and clipped and then pressed to the side where the understitching will be sewn. It helps the facing to lie flat on the inside of the garment.

      Topstitching

      Worked on the right side of the garment using a slightly longer machine stitch, this can be decorative or functional. It can be worked with double strands of ordinary thread or thicker thread. When using double thread, either put cotton reels on two spool pins or, if your machine has only one spool pin, put two bobbins (one on top of the other) on one pin!

Edge stitching

      A row of machine stitching worked very close to the finished edge. It can be used on pockets, pleats, collars and lapels as well as on the folded edge of a flat fell seam.

      Application of Zigzag Stitch

      Basic zigzag stitch in varying widths is invaluable for neatening the edge of seams or for fashioning the edges of buttonholes