Method
Different ways of tying the Czech nymphs have been described, both in Czech and worldwide literature. We use a method you may wish to try. Firstly, we tie lead wire on to the hook shank. The ends of the wire are squeezed with tweezers. The wire is fixed with a drop of super glue. Tie off the lead wire; cover with a thin body silk (after covering the body with varnish and the body silk retains its true colour). Then tie in thin double-fibre thread, tie it as long as is possible to the turn of the hook. (We experiment with different curves of the body).
Fasten; back foil, flat ribbing and nylon line. Wax the thread, dub gently with body dubbing and make the body. Remove the extra dubbing. Cut the body on the back. Rib with thin flat gold. Insert the body dubbing between divided fibres of the threads and twist, tie the belly. Add the back foil, fix it with thread on the head (Cover the back on the internal side with the pearly nail varnish - the best is the most expensive one your wife or girl-friend have!!). Rig with nylon. Tie the head, suggested that you colour mark the head according to the weight of the fly. Comb the body with Velcro and trim with scissors. Comb the Velcro again after cutting. Varnish the head, and the fly is complete.
Hooks for the Czech nymphs
After several years trying to find the most suitable hooks, it seems that the best are the Japanese hooks of Kamasan, or Tiemco. In England new hooks from Ashima "Czech Nymph" are available and recommended by Oliver Edwards.
Of the Kamasan hooks the most suitable are the following types: - B100 (thin brown), B110 (thicker brown), B100G (thin gold), B100N (thin silver), B420 (brown with an up eye). Kamasan does not produce barbless hooks, but the barb is easily squeezed and finished by smoothing with a file.
Of the Tiemco hooks the best are TMC 2487 (thin brown), TMC 2457 (thicker brown), TMC 2487G (thin gold). When using Tiemco hooks it is necessary to take into account that their sizes are not standard. E.g. TMC 2457 No.10 is in reality a size 12. Sizes of Kamasan hooks are OK. We tie the Czech nymphs in sizes 8 - 16. It is interesting that grayling often take the largest flies, even in size 6.
Weighting the flies
It is good to have all the flies in several weights; competitors use up to five weights of each size. For weighting we use leaded wire of different diameters. We use special Czech-made wire with a square profile, which is beneficial. It is produced in four diameters. When tying we may use different diameters of wires or the thinnest with more layers, possibly combining different diameters. Tying different numbers of loops etc.
After tying it a good idea to squeeze the ends on both sides with tweezers in order that there is a continuous connection between the hook shank and the bound lead. We distinguish different weights of the fly by using different colours on the end of the head. (Black -extra heavy, brown - heavy, Cream - medium heavy, yellow - light, white - without weight) or by painting the hook eyes.
Threads
The best is the thin double-fibre threads e.g. UNI Poly 11, or thread from Radek Rachac (CZ). Thin thread is important for tying a thin body. Nymphs must have the thinnest profile in order to sink fast.
Back foils
For tying backs we may use different materials. Sausage skin works very well. Flexi Body or original cut back Magic Shrimp. Magic Shrimp has the advantage that it is flexible and dyes well. One side is eggshell and the second glossy cut it as necessary for the desired width. It is produced in 25 colour shades. It is also possible to add a finishing touch using waterproof board markers (dots, stripes, etc.). For the back we use materials that are made by static imprinting, advertising vinyl foil with serigraphy. The paint (Turkey's Wing) stocked by the firm JIRI Klima (CK) under the name of Thin Skin is also very interesting. Another item being painted insect body segmentation. Called "Scud back" is also stocked by JIRI. A further material is the original wing foil Tiemco Shimazaki Fly Wings 11 stocked by the firm Zeman (CZ) under the name Flexibody.
Body Dubbing
For tying the body we use the softest dubbing we can get. Hare or opossum dubbing are both excellent. Also the synthetic "Special Dubbing) from Oldrich Dvorak (CZ) is very good and is available in some 100 colours. Dubbing may be mixed with soft pearl Angelhair; the efficiency of the flies is then quite surprising. We also use Ice Dub which is an extra soft metallic dubbing, available in 20 colours.
Dubbing for the belly
The best skin is from seal, muskrat or opossum; these contain some stronger hairs and (keep from the hare's skin, moufflon skin etc.) The belly is made double coloured. The front part (at the head) is usually dark and corresponds with the colour of the belly of the water insect. The next part (heart) is tied in a contrasting colour and has the function of being an attractor. We may then bind the end of the fly in a further contrasting colour. For a colourful belly it is best to use rougher seal's dubbing, which has a special sheen, very attractive to the fish. Alternatively use rougher Anton, which quickly absorbs water and becomes transparent. A further excellent material is the new super soft metallic dubbing Ice Dub.
Which patterns to tie?
It is best to experiment with the Czech nymphs. We may for example, tie the flies exactly according to the natural patterns of gammarus, bugs and caddis larvae. Success is assured, when we duplicate the colour (in the wet state), size and silhouette. The colour and transparency of the fly in the natural light is very important. We also tie completely fantastic and outlandish patterns, which are often more efficient than the actual real imitations. It happens, quite often, that the flies that are successful one season are not successful the next season. The very best flies are those bitten by the fish!