The F-Fly: Simple, Durable, and Ridiculously Effective (Plus Two New Tying Videos)
The F-Fly is simplicity at its best in fly tying. The result is a simple, durable, and incredibly effective fly pattern. Tie it in sizes 12 through 20; it can imitate a caddis, small stonefly, mayfly, or midge. Our favorite body colors are olive and black, but use any color thread you like. While we mainly use natural CDC, you can use any color. This versatile pattern is great for beginning fly tiers, but don’t let the ease of tying fool you—it’s a worthwhile addition to any fly fisher’s box.
Watch: The Original F-Fly
This is the clean, confidence-building version of the pattern—fast to tie, consistent, and easy to repeat across sizes. If you’re new to CDC flies, this is the perfect place to start.
Watch: The F-Fly “Sighter” Version
Same buggy silhouette, same effectiveness—just easier to track in tricky light, broken water, or when you’re fishing small flies. Tie a few “sighters” for your box and you’ll spend more time watching the fly (and less time guessing).
Why the F-Fly Works
- Simple profile, big range: In sizes 12–20 it can pass for caddis, stones, mayflies, and midges.
- CDC does the heavy lifting: It breathes with micro-currents and rides naturally in the film.
- Quick to tie: Which means you actually fill your box with them—your future self will be grateful.
Materials
- Hook: Umpqua XC120 BL (or similar barbless dry fly hook—Hanak 130BL, Fulling Mill FM5050) Size 12–20
- Thread: Semperfli Classic Waxed 12/0 (Pale Olive used in the video; also great: black, gray, brown olive)
- Wing: Natural CDC Feathers (Fulling Mill Natural or Spent Fly Fishing Medium Dun)
Tying Notes (Small Details That Matter)
- Body color: Olive and black are our favorites, but this pattern shines in just about any thread color.
- CDC options: We mostly use natural CDC, but don’t be afraid to switch to dun, darker, or even brighter CDC depending on conditions.
- Wing style: Oliver Edwards notes the original F-Fly’s wing is typically tied in and then cut to length. In our videos we use a modern, super-repeatable variation that uses the paired tips of CDC feathers.
- Feather count: For smaller flies, two CDC feathers are adequate. When tying larger than a 16, use three feathers for the right profile and float.
A Short History: The F-Fly and the Rise of CDC Around the World
The F-Fly is widely credited to Slovenian angler and fly tier Marjan Fratnik, and it’s often described as one of the earliest truly influential CDC-based patterns. The original concept was brilliantly minimal: a slim body and a CDC wing—nothing extra. That “less is more” approach wasn’t just effective on the water; it also helped change how tiers everywhere thought about CDC.
As the pattern spread, it sparked renewed interest in CDC techniques throughout Europe, and from there, CDC patterns gained traction—showing up in more boxes, more magazines, more books, and eventually becoming a standard material worldwide for emergers, duns, caddis, and all kinds of surface-film bugs. Today, the CDC is ubiquitous—but the F-Fly is a big reason it went from "niche" to mainstream.
Bonus Watch: Oliver Edwards on the F-Fly (History + Original Variants)
Stock Your Box
If you’re going to tie just a few to start, go with olive and black in sizes 14–20. They’re fast to tie, easy to fish, and effective in a ridiculous range of conditions. Simple flies catch fish—and the F-Fly proves it.
Shop the Materials
Everything used in the videos (or close substitutes):
- Hooks: Umpqua XC120 BL (or see barbless dry fly hooks)
- Thread: Semperfli Classic Waxed 12/0 (Pale Olive, plus black/gray/brown olive)
- CDC Feathers: Natural CDC (or browse CDC feathers)