Measurement, Selection and Types of Threads

Thread Measurements

The most common embroidery weight thread is 40Wt and suitable for most embroidery designs. For designs that need to be dense, you could use a lighter 50 Wt thread. Bobbin threads are finer and generally weigh 60 Wt.

3 ways to measure a thread

1.    Weight: The higher the number, the lighter the thread. Common weights are 30 wt, 40 wt & 50 wt
2.    Denier: Weight in grams of 9000m of thread. A larger number indicates a heavier thread. A number such as 120/2 equals two strands of 120 denier thread for a total of 240 denier. Denier measurements traditionally apply only to synthetic threads. Comparative note: A 40 wt thread approximately equals 240 denier
3.    Tex: Weight in grams of 1000m of thread. For Example 40 Wt. = 240 denier = Tex 25

Thread Selection

Generally, threads are selected keeping the following things in mind:
- The manufacturer and the brand of the thread. For all the hard work you put in, you obviously want the thread to be of good quality made by good manufacturers!
- The color number
- Its weight and the number of plies or strands that are twisted together
- The fiber content
- Whether or not the thread is mercerized? Mercerized cotton thread is put through a series of processes causing the thread to swell, become round or straighten out. This increases the thread's luster as well as improves water/dye absorption. Since long stapled fibers respond best to mercerization, it is usually those types of cotton that are used. Most threads currently manufactured are mercerized.
- Sometimes even the country of origin

Types of threads / Fiber content of thread

Rayon – This is currently the most popular thread used in embroidery machines. It has very good sheen and is often used as a lower cost alternative to silk threads. Stitches sewn with Rayon threads are very smooth, leading to a higher quality embroidery work. However, the disadvantage of this thread is that it deteriorates over time and needs to be maintained well.
Polyester –This type of thread is synthetically produced from polymer resins. It can be made with a matte finish to look like cotton or have high sheen finish like silk. It is a strong and economical thread. The advantage of polyester is that it won't fade or shrink when washed. It has a medium luster and can be suitable for any type of sewing. Due to its strength and color fastness, it is becoming one of the most popular embroidery threads available.
Nylon – This is another synthetically produced thread with good strength. However the disadvantages are many, like, not being heat resistant, not colorfast (becomes yellow over time) and also becomes brittle through laundering and exposure.
Cotton - This is the only 100% natural fiber thread made for high speed machines. These threads performs beautifully in machines and has a soft sheen. Embroidery floss is made up of 6 strands that can either be separated or kept together. This is usually used for cross-stitch.
The advantages of cotton threads are that they are soft, durable, easily adjust to fabric for shrinkage, it is an easy care thread and is available in various thread weights. However, cotton threads aren't as strong as polyester and do not have a distinct sheen.
Metallic / Plastic – These aren't threads actually. They are made from thermoplastic with an aluminum coating which is then cut into thin strips with a laser and wound. It must be completely unwound to be used and must be sewn with a metallic needle.
Metallic – These threads are also made of gold or silver filaments but are uncommon as it is quite expensive. These threads are blended with other embroidery threads to give a contemporary look to the finish. The quality of this thread variety could be very good or very bad. A quality metallic thread has components like nylon core, rice paper construction and an outer coating.
Silk – Silk threads are used in many kinds of embroidery. A good example will be the Victorian crazy quilts. Silk threads absorb dye extremely well and it sews smoothly without breaking. It has the strength of polyester and stability of cotton. It also has a distinct sheen due to which it is costlier than the other varieties.
Wool – Wool is an animal fiber which has a soft look when stitched, and does not reflect a lot of light. It has a soft texture. It is used for a 'homespun' effect.