No. 5 – Fishing Tips

6 July 2015 | Paul Procter

Tippet material…a question of how thick?
With new-fangled copolymers and fluorocarbons continually becoming thinner for a given breaking strain, it could be argued the X rating system for gauging monofilament thickness in relation to breaking strains is nigh on obsolete. That’s why I refer to actual diameters when selecting monos for various situations and fly sizes these days. Further complications might arise if you prefer working in old money rather than the continental millimetres, too. As metric diameters seem to appear on most spools of tippet material, for convenience, we’ll refer to them here.

Large trout are often armed with impressive gnashers that can sever or damage fine tippets if they inadvertently get rubbed across a trout’s jaw line during the fight. Equally, pools littered with boulders, tree roots, or other woody debris can play havoc with more delicate leaders when fish wrap themselves around such snags. The very same tippets are unable to turn over huge dry flies such as mayfly patterns or tungsten-loaded streamers. All these circumstances call for tippets of 0.19 mm down to 0.17 mm in diameter. 

For more modest trout and flies size 12-14, we can look to diameters of 0.16 mm down to 0.14 mm. This also applies to rivers that are less of a minefield in terms of leader-grabbing, snags too. However, once we drop below size 16 flies, for our imitations to appear more natural by conforming with surrounding currents, we should consider tippet diameters of 0.14 mm down to 0.12 mm.  Monofilaments of 0.12 mm down to 0.10 mm will only be needed in more extreme cases of sub 20 artificials, ultra-fussy fish, or where fish loiter in smooth, idle flows. 

Like many facets in fly fishing, the above are mere guidelines. There will be occasions when compromises have to be made. One example would be hefty trout feeding on midge, which require a representation no larger than a size 18. Common sense tells us this is best presented on a tippet no thicker than, say, 0.12 mm. However, landing massive specimens on gossamer-like connections is often in the lap of the gods. Increasing your tippet to something like 0.15 mm might cause some trout to baulk at your efforts, but those that do accept are more likely to remain attached!

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A trout's teeth are pin sharp and can easily damage finer tippet length in some circumstances.

Heavily-weighted flies, or those adorning generous hackles, will often twist and buckle inappropriate tippets. Be sure to step up in leader diameter when using.

Midge-feeding trout like this are obviously susceptible to smaller imitations; though there's always going to be a compromise on how fine you dare go regarding tippet diameter.