Designed by legendary Montana angler Craig Mathews, the Iris Caddis is a staple emerger pattern that excels during caddis hatches. Its defining feature is the trailing Z-Lon iris shuck, which suggests the vulnerable stage when a caddis is half-emerged and drifting in the surface film. The sparse dubbed body and upright wing keep the fly low and natural while still offering just enough visibility for the angler.

Unlike high-floating caddis imitations, the Iris Caddis is meant to ride flush in the film. It can be fished alone, as a dropper behind a dry, or in tandem with other emerger patterns to match the complexity of a hatch. Effective on spring creeks, tailwaters, and freestones alike, this simple yet deadly fly has earned its reputation as a must-carry whenever caddis are present, especially for technical trout.