Put simply, specialty threads are those that differ from the standard 40-weight polyester or rayon threads. They are different in thickness, sheen, coloration, and fiber content, and may or may not have a special effect. Common specialty threads include metallics, mattes, thick threads, thin threads, variegated, ombré, twists, fluorescents, glow-in-the-dark, and solar color-changing threads.
In short, they stand out. Almost all embroidery is done with thread of a similar thickness, coloration, and surface quality. So, it stands to reason that threads that differ from the norm will catch the eye. Embroidery in the commercial sphere often takes the form of something promotional. It almost always has an end goal of garnering attention and/or conveying a message. Even the most subtle tone-on-tone design can still communicate a message, even if that message is, "this logo is meant to be subtle, not gaudy, just like the company/group it represents."
Promotional products are incomplete in their execution if they can't bring attention to the brand or message that they attempt to convey, and embroidery is no different. Specialty threads serve as a tool to help designs break away from the standard modes of decoration, without necessarily relying on a redesign of the underlying image.
Specialty threads can also alter or bolster the intended feeling a decoration is attempting to evoke. They offer a chance to change the initial impression one might associate with an image rendered in traditional 40-weight polyester and rayon.
Source: Erich Campbell
Check out Printwear's upcoming May issue for a special feature on varius thread types, their pros and cons, as well as best uses.