Selecting the right type of threads for any embroidery work is important because the color and texture of the design, and eventually the look of the final product depend on the material and type of thread used. Theres a wide variety of embroidery thread to choose from, so take your time to decide what type or combination should be best for the design you have in mind. More importantly, thread selections should be based on Sewability, Seam Performance and Appearance, Availability and Cost.

Types:

1. Rayon: This type of thread has a great sheen, and so the best looking embroidery designs are stitched with it. Rayon threads can range from combinations of two or more colors twisted together thereby forming a single strand, to one solid color strand. They are widely available, mostly in standard 40 wt. and 30 wt. Even though Rayon is the most popular type, its not very sturdy because of its thinness.

2. Polyester: Polyester thread is more durable than Rayon but it is not as attractive. However, this type of embroidery thread hardly shrinks or fades, and if combined with Rayon, the effect they provide is nearly indistinguishable. It is also cheaper than Rayon thread.

3. Cotton: Cotton thread allows for a wide range of tension adjustments because of its texture. It has a nice sheen, is quite sturdy (though finer threads above 50 wt. are not), and typically used for machine embroidery.

4. Silk: Silk embroidery thread hardly breaks and has its own unique, and probably the best sheen. Threads come in various sizes but their availability is low so they are mostly used for luxury fabrics.

5. Metallic Thread: This type of thread has a core wrapped with a metal foil which may be coated with silver alloy, and color is added to this foil with a polyester film which may also be applied as an undercoating. Metallic thread is one of the most durable available on the market.

6. Mylar Thread: Plies of film are combined into a layer, cut into slices to create Mylar threads. They are durable but may break under high-speed sewing. One unique color feature is holographic hue, which picks up and reflects light or color from other surrounding objects. This really enhances the color and design of the embroidery.

7. Special-effect: Like the name suggests, this type of thread can be used to create different design effects, such as crewel-like effect. Some of the special effect threads change colors under sunlight, or may glow in the dark.

Quality Evaluation:

1. Tensile Strength: The tensile strength of an embroidery thread can be tested by sawing a suspended strand with another strand back and forth until the first strand breaks. The faster it breaks, the lower the strength and quality of that particular thread type.

2. Elongation: A good thread must have the right amount of stretch. Take a piece of the thread and stretch it till it breaks. The strand should neither break too quickly nor stretch for too long.

3. Sheen: The luster and quality of the sheen can be tested by studying the color and design of a finished embroidery product.