Proportion
Proportion is critical to construction of a high quality nymph. Certain bugs just simply look a certain way, and as anglers, our job is to make our flies look like those bugs, or at least embody the features that these insects possess. Typical proportions vary depending on bug species, but can be generalized within overarching bug types. For example, swimming type mayfly nymphs tend to be slender and longer than their clinging mayfly nymph friends, which are usually shorter and broader. In order to aptly represent the proportions of a swimming mayfly nymph, the fly tyer should aim for a slender, and usually longer, abdomen, with an abrupt taper to a thorax. If tying a clinger nymph, the same tyer would want to aim for a much thicker abdomen that tapers more gradually to an already thicker thorax. Different proportions exist in much of tying, but the goal in briefly addressing it is to highlight the importance of properly representing it in your tying, not to provide an extensive list of “correct” and “incorrect” proportions. Euro style nymphs are tied in a variety of ways, and don’t hold to any one set metric of proportions. In any style of tying, the different patterns should vary in proportion in order to appropriately represent the insect that is being imitated, or at least the style of fly that is being tied. Most perdigons are slender and exhibit a long taper, but that doesn’t mean all perdigons must apply this metric. Most stonefly nymphs and caddis pupa style patterns are on the thicker side, with more drastic tapers, but this doesn’t mean that all stonefly and caddis imitations need to follow any presupposed “rules”. In any case, the goal should be to understand what proportions you are aiming for, understand why you are aiming for them, and then achieve those proportions in a consistent manner, across all of the individual flies where these proportions apply.