The Use of Thread

By:  Ed Gallop

Thread Comparison Chart

Silk threads were used for fly tying long before nylon and polyester came on the market.  Silk is still used by tiers of classic flies and by those that simply prefer it.  However, the most commonly used tying thread is polyester, followed by nylon, and then silk.  Personally, I have all three on my desk and each has it's own specific use.

Polyester is easier to handle so is used for most of my tying needs.  Nylon monofilament has brighter colors and is stronger.  However it has an undesirable smoothness, stiffness, and it stretches.  It's strength and smoothness is an asset when spinning hair (flaring for hair bugs) but the stiffness and smoothness make it harder to handle and causes it to slip on the hook.  I also believe the stretch characteristic of nylon monofilament may cause it to relax over time and thus slightly loose it's grip.  It will not lay as flat as most polyester but the colors make nice bright heads.

Thread Chart:  Below is a thread chart with breaking strength and denier estimates for several threads to help you select the best thread for your needs.  Most tying thread use diameter measurements (example; 3/0, 6/0, 8/0, etc) but Denier measures weight.  Denier is the number of grams in 9,000 meters and it is used in the textile as a means of measurement.