The All Round Olive Barbless is a dependable, general olive dry fly for UK rivers, designed to cover several small upwinged duns rather than one exact species. Its olive body and conventional dry-fly outline make it a sensible searching pattern when trout or grayling are looking up but the naturals are too sparse or distant to identify confidently.
Fish it upstream on a tapered leader and protect the drift with careful mends or a reach cast. Match the fly's size to the insects on the water and use it through glides, riffle edges and seams. It is particularly useful on small streams where a simple, visible olive imitation can cover broken water efficiently. One solid take is often enough to make this a trusted favourite.