This is by far the best tippet material available on the market. Stroft means STRong and sOFT and it really is. Used with the knots recommended (shown on the spools) you can get almost 100% knot strength which is superb. Stroft GTM is a blue grey transparent polyamide which is stunning for dry flies or nymphs down to even the smallest sizes.
What does the EFTTA seal of quality mean and how is it achieved?
As a couple of years ago more and more fishing lines with unrealistic breaking strains came on the market the EFTTA (European Fishing Tackle Trade Association) reacted and set up a neutral test procedure in a laboratory in Great Britain. Since then all manufacturers are able to have the diameter and breaking strain of their lines neutrally verified. When the manufacturer’s values correspond with the test results then they are awarded the EFTTA seal of quality. Further information to the EFTTA line test can be found here: www.EFTTA.com. As of now the consumer has the opportunity to separate the wheat from the chaff and buy verified, quality products that carry the EFTTA seal of approval. One should certainly wonder why some products do not carry the EFTTA seal of approval, particularly when the breaking strains seem comparatively high.
What does line test, breaking strain and tensile strength mean?
The breaking strain, or line test of a fishing line describes the maximum amount of force that a line can pull before it breaks. We use the term “(Fmax)“. The correct unit for force is actually N (Newton). 9.81 Newton = 1kp, but this is somewhat depending on one’s geographical position (Kilogram is actually the unit of mass and does not depend on the strength of gravity). For example, an object that weighs 1kp on earth would weigh slightly less in some places on earth and a lot less in outer space (weightlessness). The mass, however, stays the same no matter where it is exerted. But as there aren’t many fish on the moon it’s okay to rate line strength in kg or indeed lb (pound) as in Great Britain or America. The tensile strength (Rm) of a line is the result of dividing the breaking strain “(Fmax)“ with the area of its cross section (S). This results in (Rm = Fmax / S) and is expressed in kg/mm2. Conversely, it’s easy to work out the breaking strain of a line by multiplying the tensile strength (Rm) with the cross sectional area (S) which gives (Fmax = Rm x S), the breaking strain. If the line is round then the cross sectional area (S) can be worked out using the diameter (d), then (S=d2 x 0.785). Every angler does this subconsciously as the breaking strain alone is not an indicator of the tensile strength of a fishing line. The breaking strain is only of relevance in connection with the diameter or cross-sectional area of a fishing line. The tensile strength (in relation to the prevailing conditions; hot, cold wet, dry without knots and knotted) is only one of many different properties that are of relevance for fishing lines. However, it is the singularly most important property. Also, tensile strength strongly influences many other properties. The finer the fishing line (in relation to its breaking strain) the lower is its visibility, the memory, the elasticity and the water resistance – lures work better, bait presentation is more natural, sensibility is increased, casting distance and accuracy are improved.