Tuesday, July 27, 2021

Film Flies
Presenting your flies not too high, and not too low, produces results when trout are feeding near the surface.
By Boots Allen

A box dedicated solely to film flies can come in handy on most trout streams and lakes.

Organizing fly boxes is a time-honored tradition. Many see it as a requirement for success. For others, “getting ready” has always been part of the fun in this game we play, and nothing means being ready like well-organized boxes.

Saltwater anglers tend to arrange their boxes by species or forage types. Fly fishers targeting steelhead or salmon generally organize their boxes by type of patterns—say tube flies in one, articulated patterns in another, and single hook flies in yet another. Warmwater fly fishers may separate their boxes by baitfish, crayfish, aquatic invertebrates—like damselflies and midges—and surface patterns like amphibians and poppers.

Trout anglers regularly carry the most boxes due to the range of possible scenarios we might encounter on the water. Many of us have boxes dedicated to attractors and terrestrial patterns. Chironomids, mayflies, caddis, and stoneflies generally occupy their own space. And we often carry boxes specific to dries, nymphs, and streamers.

My boxes are largely based on the descriptions above, with an exception: I carry a box of flies meant to be fished in, or just under, the surface film. I call these patterns film flies.

Film Fly Breakdown
I define a film fly as any pattern meant to be fished on or near the surface that represents trout forage at its most vulnerable stage of existence. This is key to the pattern’s effectiveness. Emerging mayflies are a prime example. Emerger patterns imitate flies either struggling to free themselves from their shuck while on the surface, or struggling to break through the elastic tension caused by the water’s surface film. Naturals cannot swim or fly when they are in their emergent phase—instead they’re dealing with more immediate challenges, like wriggling from a shuck or drying their wings. At this stage of life, they are easy pickings for trout.

That said, I consider other patterns imitating other invertebrate life stages as film flies. Chironomids and caddis go through a complete metamorphosis that allows fly fishers to imitate the pupal stage of these insects. Midges and caddis must escape the pupal shuck to reach the adult stage, and their escape often occurs in, or just under, the surface film. These bugs are as vulnerable to feeding trout as emerging mayflies.

You can also consider spinner imitations as film flies. These patterns mimic dead or dying aquatic insects that lie flush in the film or sometimes slightly underneath it. Spinners generally don’t move so they are the ultimate easy pickings for trout. Tricos, brown and green drakes, PMDs, spent caddis all fall into this category and are, at times, the most productive stage of various hatches to match.

Aquatic invertebrate imitations are not the only imitations that qualify as film flies. You can also productively fish terrestrial patterns in or just under the film. Once on the water, most grasshoppers, ants, and beetles are unable to make it back to dry ground. They all eventually drown if a trout doesn’t consume them first. These bugs can elicit a fair amount of movement when they are both in and under the surface film. But once drowned, they are simply drifting with whatever current there might be. Either way, hungry trout have access to them, and during the dog days of summer, terrestrial imitations can be the only game in town on some waters.

But trout feed on film flies for more reasons than just easy access to vulnerable bugs. Often there are massive amounts of food at their disposal when these flies are in the film. I observed a green drake hatch on the South Fork of the Snake River in Idaho that had far more emergers than full-fledged adults. Close examination made it clear that trout were focusing their attention on those drakes still trailing a shuck. Secondarily they were taking duns. Fish in lakes and reservoirs can behave in a similar manner. On some stillwaters in Yellowstone National Park and other parts of western Wyoming, wind can blow massive numbers of carpenter ants from surrounding foliage and onto the water. After a period of time, the ants are saturated with water and descend just below the surface, where fish start to feed on them in a gluttonous manner.

Another reason why film flies work is because trout feel comfortable taking those patterns in or just under the surface. By nature, trout more often than not rise to their forage as opposed to diving for prey. Forage is easy to find when the bug’s body is silhouetted against a bright sky. Since trout are always on the lookout for potential predators in the form of eagles and ospreys, it’s easy to assume that feeding just below the film is instinctually safer for fish versus being right up on the surface.

All Shapes and Sizes
What makes a good film fly pattern? The most important requirement is that it does what the naturals do—it lies in the surface film. If not in the film, it should be just below it. Any kind of film fly, be it a traditional pattern with decades of production behind it, or the newest and latest hot pattern, needs to meet this requirement.

Emergers and cripples are classic patterns purposely designed for anglers fishing in the film and often imitate the mayfly emergent phase. Most of these patterns share four traits—a trailing shuck, compressed body, protruding wing, and a jumble of legs. Now consider flies like the Quigley Cripple, Quigley’s Film Critic, Cole’s Split Wing Cripple, or Booty’s Green Drake Emerger. All contain these four traits. Where they differ is how each body and hook lies in the film. Some are tied on straight-shank hooks and built to lay flush on the surface with the shuck and part of the abdomen in, or just under, the surface. Others are tied on curved nymph hooks, similar to the hook used for a Klinkhamer Special, and constructed in a manner so only the wing and a portion of the thorax project from the surface. The rest of the fly is submerged under the surface film.

Other patterns are tied so much of the body suspends below the surface and just a small portion of the fly touches the film or protrudes above it. Generally, the part of the fly touching or protruding from the film is the wing or the wing case. Some materials are ideally suited to imitate the wing or wing case while at the same time providing the slight buoyancy needed to suspend the fly correctly in the water.

Five millimeter razor foam is a favorite material for use in forming wing cases, as is box sheeting, poly yarn, CDC, and EP Fibers. Just a small tuft or clip of one or the other is needed. Some tiers marry the wing case and wing by placing a small slit in the case material and wrapping each slit piece around the wing. Doing this provides additional buoyancy, although many times it’s not required.

Still, other patterns are intended to work well underneath the surface film, although not by more than a couple centimeters. The most popular are caddis pupa imitations intended to be fished and swung at the end of a drift. Strikes generally occur as the fly is swinging just underneath the surface. In fact, the take is often so close to the surface that it’s easily visible.

Soft hackles (or patterns with a CDC wing) are another long time, tried-and-true pattern when either worked in the film, or swung off single-handers or specific trout spey rods, often to imitate caddis pupae. Several patterns, tied on large size 10 to size 6 hooks, imitate drowned stoneflies and grasshoppers. Typically, you can tie body materials, like rabbit fur dubbing, Polar Fiber, or fox fur, onto the hook in generous portions and tease it out so water easily saturates and helps sink the fly just below the surface.

One of my favorite “outside the envelope” tying techniques is to add a parasol indicator to my ant, beetle, and chironomid patterns. The parasol—made of yarn, wool, foam, or a similar material—floats in the film, but connects to the fly via monofilament or piano wire. The fly rides suspended just under the film, sometimes by a couple of inches, and other times, by just a centimeter. Film patterns designed in this manner are among my favorite when trout are feeding just below the surface in shallow riffles and flats or in swirling foam eddies. To make these flies easier to see, use a fluorescent-colored parasol. The fly will slip through the foam to where fish are eating, and the bright color (which the fish can’t see) will stand out against the color of the bubbles and make it easy to detect a take.

Challenges and Remedies
Film flies are productive patterns that, at times, can outperform both larval imitations fished deep in the water column, and high riding adults. The great part about fishing these patterns is you’re still targeting fish close enough to the surface that takes are easy to detect when they occur. Nonetheless, most of the patterns illustrated here are intended to be fished in or just below the film, and keeping a visual on them can be difficult at times.

You can remedy this by using small amounts of floatant on those parts of the fly meant to protrude from the film, particularly the wing and hackle, and in some cases, part of the thorax. These materials will float while the shuck and abdomen lie in or just below the film. You can also apply floatant to the wing case and wing on those patterns meant to be flush or just under the surface.

That said, some film flies are meant to be difficult for anglers to see. If gaining a visual on the fly is too challenging, one solution is to secure a small piece of hi-visibility wool or yarn to your tippet approximately one to two feet from the fly. The wool will be in close enough to the fly to allow a fly fisher to easily see a take and set the hook at the right time. By no means is this a new form of tackle or tactic. Anglers have been fishing yarn indicators with their film flies for several decades. In fact, there are several commercial brands of wool indicators on the market specifically designed to be used in this manner.

On the opposite end of the spectrum, film flies run the risk of riding too high on the surface or not enough beneath the film. Using split shot or a sinking solution can be overkill, causing the fly to descend too low in the water column. A better remedy is to focus on the leader material. You can apply a degreasing agent, like Loon Products’ Snake River Mud, to the first three or four feet of the tippet above the fly. This allows the section of leader to cut through the surface film during the drift or swing. The fly will slowly make the same descent, but rarely sink more than half an inch. Another option is to use a small piece (four to eight inches) of fluorocarbon as a tippet section between the fly and the leader. The fluorocarbon will perform the same as a degreased monofilament leader by slowly descending through the film, making the fly slowly descend as well. Of course, fluorocarbon has a bad reputation for its high biodegradable threshold. If it breaks, whatever is on the water will be there forever. My advice to those using fluoro material is simple—use as small of a piece as you can, be confident in your knot tying abilities, and never break that tippet on a snag or a fish.

Degreasing agents can be applied to leader material, allowing the mono to descend slowly in the water column. It is ideal for film flies that are riding too high on the surface.

Film Flies Patterns

Cole's CDC Split Wing Cripple

Cole’s CDC Split Wing Cripple
Hook: Tiemco 100, sizes 14-22
Thread: 8/0 Uni-thread, Olive Dun
Tail: Cream or Amber Z-lon topped with wood duck breast feather
Abdomen: Stripped peacock herl, stripped hackle tip, or light olive dubbing
Wing Case: Olive CDC feather
Thorax: Olive dubbing
Wing: Poly yarn, Silky Fibers, or calf tail

Booty’s Drake Emerger

Booty’s Drake Emerger
Hook: TMC2487 or equivalent, #10 to #12
Abdominal Thread: Flat wax nylon, color to match natural
Shuck: Ostrich herl, tied in long but sparse
Ribbing: Fine brown thread or monocord
Abdominal Coating: Softex or other clear adhesive
Wing: EP Fibers, color to match natural
Wing Support Post: 2mm closed cell foam, cut into a V at one end so that it fits around the wing, color to match natural
Legs: Z-lon, color to match natural
Hackle: Brown rooster
Dubbing: Squirrel dubbing, color to match natural

Mercer’s Glasstail Caddis Pupa

Mercer’s Glasstail Caddis Pupa
Hook: TMC 2457, # 12 to 18
Thread: Olive 8/0 Uni-Thread
Thread for Extended Body: Small diameter black or gray Kevlar
Extended Body Beads: Olive, tan, or brown glass
Body Beads: Olive, tan, or brown glass
Head Bead: Clear glass
Body Dubbing: Hareline Dubbin’s Hare’s Ice Dub, olive
Antennae: Lemon-barred wood-duck flank fibers
Legs: Indian hen saddle feather
Collar: Peacock Herl

Boots Allen
Boots Allen is a fly fishing guide and writer who lives with his wife and two kids in Victor, Idaho. His latest book is Finding Trout in All Conditions.