Danville's replacement for the time-honored 3/0 Monocord. This 140 D thread is strong and lays flat. All thread is different and everyone who has tied for a long time has their favorites as well as understands what each type and brand does best. This is an all-around great performer for medium to large size flies of all types. even spinning deer hair if you work within the limits of the material. Great color selection even though thread color is probably the least important aspect of any fly. I use 70 D Danville and this 140 D for probably 90% of my tying.