Threads for quilters

Thread construction

Twisting together short fibres or continuous filaments produces sewing threads. This is known as 'singling twist' and is responsible for the strength and flexibility of the thread. If two or more yarns are combined to make the thread, a 'reverse thread' is applied to add balance. It is important that a reliable sewing thread has a well-balanced twist. Once the thread is made, it may be finished in various ways, depending on its purpose. Cotton may be mercerized - stretched and treated with a caustic solution to strengthen it and make the colour of the dye deeper. Cotton threads may also be gassed, which reduces the fuzz and results in a higher sheen, or glazed, which results in a hard finish. Nylon or polyester thread may be bonded - treated with a special resin to add a smooth coating.

Spun threads are made from cotton or polyester staple fibres that are spun into single yarns and then multiple yarns are plied to make a sewing thread. They have a slightly fuzzy surface that makes them soft to handle.

Core spun threads are made by spinning a wrap of either cotton or polyester around a polyester filament core. Two or more of these are twisted to form the thread. The polyester core makes a strong thread that doesn't stretch easily.

Continuous filament threads are made by extruding individual filaments of synthetic material and then applying a single twist.The unbroken fibres are then brought together and a finishing twist is applied. This results in a strong sewing thread.

Monofilament threads are made from a single synthetic filament that is extruded to a specific diameter. These threads are often used because the thread is translucent and blends with many colours. Care needs to be taken with monofilaments, as they are often heat-sensitive.

Textured threads are made from continuous filaments, which are twisted then heat set, which produces softness and bulk.

Thread sizing and weight

There is no agreed standard for threads used in the home sewing market, but the Tex system has become the standard for industrial sewing thread. As a general guide, heavyweight threads are Tex 40-Tex 90, medium weight threads are Tex 27-Tex 35 and lightweight threads are Tex 10-Tex 24. Thread weight is a different measurement system entirely and is based on a calculation using the cotton count system. Filament threads, such as rayon and polyester, are usually measured in denier. To work out the thread weight, the denier size must be converted to cotton count. The smaller the number of the thread weight, the heavier the weight - a 27-weight thread is much heavier than a 50-weight thread.

A thread for every use

We quilters have become increasingly adventurous with our use of threads and can choose from the enormous range available in cotton, rayon, polyester, silk, and wool. Many are available in our favourite quilt shops, while an even wider range is available through mail order from online suppliers.

Cotton threads are always popular with quilters, especially for those who work exclusively with cotton fabrics, but they can dry out if stored for a long time and this can cause the thread to snap. Many colours of cotton sewing thread are available, while cotton is also available in special quilting threads with glazed finishes and in threads for hand embroidery, candlewicking and sashiko. Brands that offer 100 per cent cotton thread ranges include YLI, Madeira, Mettler, Aurifil, Robison-Anton, Sulky, Superior Threads, Valdani, Gütermann, Signature and Olympus.

Cotton wrapped polyester core threads are most popular with quilters who like the strength from the polyester core, but the suppleness that the cotton cover provides. Some quilters are concerned about using a thread that's stronger than the fabric in their quilts in case the thread cuts into the fabric. This may be of concern with quilts that are handled frequently. Brands that offer cotton wrapped polyester core threads include Gütermann, Rasant, Signature, Mettler and Coats.

Rayon threads are often used for decorative effects as they have high, silky lustres and shiny colours. Silk threads are often popular for appliqué because they are fine and soft and also have an attractive lustre. Brands of rayon threads include YLI, Madeira, Sulky, Isafil, Victory, Coats & Clarke. YLI and Gütermann produce silk threads. Wool blend threads, such as those available from YLI, give a crewel embroidery-like texture and can be used for hand work as well as in sewing machines.

Many different effects can be achieved with specialty threads. For a quilted look without showing the actual stitches, monofilament thread - such as that made by Madeira, Sulky and YLI - can be used for machine quilting. Metallic threads can add sparkle to quilts. YLI, Madeira, Aurifil, Superior, Kreinik and Sulky all offer stunning colours in their metallic ranges. Originally designed as a wash-away basting thread, water-soluble threads such as those made by YLI, Superior and Aurifil can be used wherever a temporary hold is required, such as for trapunto designs or appliqué. Also available to aid stitching are bobbin threads, such as those made by YLI, Signature, Superior, Madeira and Echidna. These can blend with top threads to become invisible. To guarantee even thread-winding onto the bobbin, you can even buy prewound, disposable bobbins.

There is an extensive range of novelty threads for quilters looking for extra embellishment options. These include wool and synthetic yarns, such as textured wools, chenille, nylon tubular ribbon, mohair, boucle and ribbons. You can even buy threads that glow in the dark, such as those from Superior, Aurifil and Kreinik. Quilters are truly fortunate to have such an extensive range of threads available today. Different fibres are available for use depending on each quilter's preference and the range of colours is stunning. Who would have thought that one day quilters would collect threads for their stashes as well as fabrics?

If you are interested in learning more about the structure of sewing thread, YLI Corporation has produced a document called A Thread of Truth: A factual look at sewing thread which explains how thread weights are calculated and how cotton counts are converted to Tex. This is available from their website http://www.ylicorp.com/ and has useful explanations of all the calculations involved and recommended needle sizes for each weight of thread.