Adapted from L.L. BeanFly-Fishing Handbook by Dave Whitlock

Artificial flies can deceive fish into mistaking them for the real thing. There are five basic kinds of flies: dry flies, wet flies, nymphs, streamers, and bugs.

Dry Flies

If the real insect is active on the surface, you should attempt to impart a similar action to the artificial. On the other hand, if the natural is inactive, the imitation should also be inactive. Wind, variable horizontal current speeds, or both of these forces will often cause drag on the fly line, leader, and fly. Drag causes the imitation to move unnaturally. It can usually be avoided by proper presentation and mending of the fly line.

An Elk Hair Caddis dry fly

Most dry flies are designed and tied with materials that allow them to float partly above or in the water's surface film. However, if not treated with a waterproofing agent such as silicone or paraffin, they usually will soon become wet and sink. This is especially true when a fly has undergone repeated dunkings or has caught many fish.

Use a dry-fly spray or paste to waterproof the fly before you use it. Put on just enough to coat the entire fly very lightly. Sprays and liquids are a little easier to apply, but they are more expensive and do not last as long as the paste dry-fly flotants. Pastes will usually liquefy with the warmth of your fingers and solidify when fished.

If the dry fly begins to float too low or sink and does not improve after several water-removing false-casts, retrieve it and blot with an absorbent paper or cloth towel, tissue, or chamois leather. Absorbing the excess water will lighten the fly and serve also to clean it. Apply another coat of dry-fly dressing, and the fly should float like new. An absorbent towel or chamois is also very useful for cleaning and drying the fly after you remove it—wet, slimy, and matted—from a fish's mouth.

Wet Flies

Wet flies sink just below the surface or deeper and generally imitate aquatic insects swimming, emerging, egg-laying, or drifting helplessly in the water. Some wet flies also imitate small fish or submerged terrestrial insects. Wet flies can be fished with floating, sinking-tip, or full-sinking fly lines, depending upon the depth and angle of the desired fly movement.

A basic wet fly

On calm water, wet flies are usually presented on the far side of where you suspect a fish is swimming. The fly is then allowed to sink to the right depth. Then, with whatever action and speed will imitate the natural insect or small minnow, the fly is retrieved to and past the fish.

Many wet flies are made in highly colorful attractor or exciter patterns, especially those used for brook trout, bass, shad, panfish, salmon, and steelhead. These attractor flies are generally fished faster and in a less imitative manner in an attempt to attract and excite the fish.

Wet flies in moving water are generally presented in front of and just above the fish's position. They are drifted downstream or retrieved across or upstream, depending upon what they are designed to imitate and how they are meant to attract or excite the fish.

Some wet-fly methods use more than one fly on the leader (check regulations for waters you fish). Sometimes as many as six wet flies are used, although two flies are much more common. Multiple wet flies are usually fished on and just below the surface.