Cores and Coatings February 16, 2015 – Posted in: Basics

The core: the backbone of every Scientific Anglers fly line.

In the world of fly lines, you’re only as good as the core you build upon. Without the right core materials, lines wouldn’t stand a chance against the harsh environments Mother Nature has up her sleeve. Over the years, we’ve dedicated hours upon hours to constructing optimized cores for every fish, every environment, and every angling situation imaginable.

core 1

A core determines the line’s strength, stretch, and stiffness. Altering one affects the other two.

core 2

Our hollow, braided multifilament cores are more supple and more suitable for all weather conditions.

core 3

Our stiffer braided monofilament core reduces tangling and is ideal for warmer, tropical waters.

The coating: where Scientific Anglers’ technology shines.

A fly line without a solid coating is just like a car tire built without any tread. It might get the job done for a while, but it won’t be pretty in the end. As with our cores, we’ve spent countless hours developing and maximizing the performance of our fly-line coatings. We’ve created lines that last longer, float higher, and shoot farther—all thanks to the breakthroughs we’ve made with our coating technologies.

Ultra Core

Our Advanced Shooting Technology (AST) slickness additive is built into the coating itself, meaning AST will last as long as the line does.


Glass microballoons, applied in different amounts in different lines, allow us to control the density of our floating lines.


Using powdered-tungsten in our sinking-line coatings allows us to create denser, environmentally safer lines.