In the intricate art of seed beading, where uniformity and tension are paramount, the choice of thread plays a decisive role in the durability, structure, and overall success of a project. Among the many thread options available to beadworkers, two stand as the most frequently debated and utilized in the community: Fireline and Nymo. Each represents a different approach to thread construction, performance, and suitability for specific techniques, and over time, they have established their own standards and expectations within the world of fine beadwork.
Fireline, originally developed by Berkley for use as a high-performance fishing line, is a thermally bonded, braided polyethylene thread classified as a type of gel-spun polyethylene fiber. It was later adopted by the beading community for its unmatched strength, resistance to fraying, and low stretch characteristics. It quickly became a staple in seed bead weaving, particularly for structural pieces or designs involving multiple thread passes, such as right-angle weave, cubic right-angle weave, and three-dimensional peyote. Fireline is available in various weights, typically measured in pounds, with the 4 lb and 6 lb varieties being the most commonly used in beading. The 6 lb Fireline has a diameter of approximately 0.008 inches (about 0.20 millimeters), while the 4 lb variant is closer to 0.006 inches (about 0.15 millimeters). Though marketed in pound-test strength, which originally referred to its tensile capacity in fishing applications, these weights have become quasi-standard indicators of thickness and stiffness in beading circles.
Fireline’s durability is one of its key advantages. Its high abrasion resistance makes it ideal for working with sharp-edged beads such as cut glass, crystal, or certain metal-lined seed beads that might shred more delicate threads. It holds tension extremely well, maintaining the crispness of beadwork over time without sagging. However, because of its stiffness and somewhat slick surface, Fireline can be more difficult to knot securely, and it may leave small, visible exit holes if too much tension is applied. It also has a tendency to retain kinks or coils from being spooled, which many beaders counter by stretching or running it through their fingers prior to use. Fireline typically comes in neutral tones such as Crystal, Smoke, and Black Satin, offering enough versatility for most projects, though it lacks the color variety of traditional nylon threads.
Nymo, on the other hand, is a nylon-based monofilament thread originally developed for the leatherworking and shoe industry. It gained popularity in beadwork during the latter half of the twentieth century and has remained a trusted standby for many traditional beaders and Native American artisans. Nymo is known for its smoothness, flexibility, and ease of handling. Unlike Fireline, which is braided and thermally bonded, Nymo is a flat, twisted thread, making it more pliable and easier to knot. It is available in a wide range of colors and sizes, allowing for more nuanced blending with beads and better concealment within finished work. The most commonly used sizes in seed beading are Size B and Size D. Size B has a diameter of about 0.20 millimeters, while Size D is slightly thicker at around 0.30 millimeters. These size distinctions have become a de facto standard in many pattern instructions and materials lists.
Nymo’s softness makes it particularly well-suited for loomed work, flat peyote, and bead embroidery, where a flexible drape is desirable. It threads easily through beading needles and conforms well to the contours of fabric and curved bead surfaces. However, it is more prone to fraying, especially when passed multiple times through small bead holes, and may not hold up as well under tension compared to Fireline. To mitigate these issues, many beaders condition Nymo with beeswax or synthetic thread conditioner, which strengthens the fibers, reduces tangling, and improves longevity. Despite these precautions, long-term wear, exposure to moisture, and repeated abrasion can still degrade the thread over time.
Another important distinction between the two is their interaction with needles and bead holes. Fireline’s rigidity can be advantageous for stitching with precision, but it can also place stress on bead edges, particularly if the thread hole is tight. Nymo, by contrast, is more forgiving in tight spaces, but its elasticity can sometimes allow for slippage or irregular tension if not carefully monitored. The difference in handling characteristics means that many professional beadworkers will select one or the other depending on the specific requirements of a project. For example, a sculptural beaded vessel or a tightly woven bracelet with significant structural needs might call for Fireline, while a soft, draping collar or a piece requiring vibrant thread coloration might be better served by Nymo.
Both threads have become benchmarks in the seed beading world, with project instructions often specifying not just the type but the exact size or weight to use for best results. As the industry has matured, more brands have emerged offering alternatives, such as Wildfire, DuraThread, and KO thread, each with their own properties and fan bases. Yet Fireline and Nymo continue to serve as the twin pillars of seed bead threading, each with its own lineage, handling style, and standard measurements that experienced beadworkers rely on with practiced familiarity.
Choosing between Fireline and Nymo is not simply a matter of preference; it is a matter of understanding the demands of a design and matching those needs to the technical strengths of the material. In an art form where every fraction of a millimeter matters, where thread tension can define the difference between elegance and distortion, these threads form the unseen but essential skeleton of beadwork. Their properties, defined through years of use and refinement, have become a silent standard—an invisible framework that holds the shimmering architecture of glass beads in perfect, enduring alignment.