Catgut Biothread

Absolutely perfect for making bodies for nymphs and emerger flies. Also a great choice material for making loops on traditional salmon flies (small diameters, in particular, XS and S) See the Description section below for more details, tying instructions, and more!

• One of the best materials for tying killer, super-realistic nymphs.
• Unique and versatile - a top choice material among the world's most experienced fly tyers.
• It is opaque, solid-colored when dry, and becomes milky translucent and shiny when wet.
• When submerged in water, it becomes very soft, flexible, and stretchable, which makes it super easy to work with.
• As it soaks in water, its volume also increases, giving a plump appearance to the fly.
• The most amazing benefit of using this material is the way it looks in water - flies tied with it look extremely authentic, have lifelike texture, and super-high shine.
• The material has been treated to extend its durability under water.
• To apply, soak the part you want to use in warm water for 3-5 minutes prior to tying. The color will change from opaque to more milky and transparent and the material will be super-flexible and easy to wrap.
• When the fly dries, the body will go back to its solid-colored state.
• By using various colored threads underneath it for the underbody, different effects can be achieved as the color peaks through the wet material.
• About 50 cm long (about 20''), comes in four diameters and a wide range of colors.
• Sizes (Diameters) and hook recommendations: Extra Small (0.18mm) - for hooks #16 and #20
• Small (0.3mm) - for hooks #14 and #16
• Medium (0.5mm) - for hooks #12 and #14
• Large (0.7mm) - for hooks #8 and #10
• Absolutely perfect for making bodies for nymphs and emerger flies.
• Also a great choice material for making loops on traditional salmon flies (small diameters, in particular, XS and S)
• See the Description section below for more details, tying instructions, and more!