Flatbow A flatbow is a bow with non - recurved , flat , relatively wide limbs that are approximately rectangular in cross - section . Because the limbs are relatively wide , flatbows will usually narrow and become deeper at the handle , with a rounded , non - bending handle for easier grip . This design differs from that of a longbow , which has rounded limbs that are circular or D shaped in cross - section , and is usually widest at the handle . A flatbow is usually just as long as a longbow . Traditional flatbows are usually wooden selfbows ( bows made of one solid piece of wood ) , though laminated and composite flatbows have been made in ancient and modern times . Modern flatbows commonly use fiberglass . Advantages of a rectangular cross - section . The flatbow is a superior bow design for almost all materials because the stress is more evenly spread out than with rounded limb sections . A bow limb is essentially a flexed beam undergoing bending , and in any flexed beam the farther from the neutral axis ( line in the middle of the flexing beam which is not under tension or compression : see diagram in Bending article ) the more stress there is within the material . When a limb is rounded , as in a longbow , some material " sticks out " farther from the neutral axis , and thus is put under greater stress . In a flatbow , the flat belly and back ensures that all of the most highly strained material is a uniform distance from the neutral axis , spreading the load over a wider limb , minimizing stress and making weaker woods far less likely to fail ( break or become permanently bent and lose the springiness needed in a bow ) . Only particularly resilient timbers can make an effective and powerful wooden longbow . Suitable timbers . In most parts of the world , common hardwoods may be used to create excellent bows . Suitable and easily - available timbers include elm ( used in ancient Europe , as evidenced by bows pulled from European bogs ) , maple , sycamore , hazel , and ash . The flatbow design also lends itself to very dense , high strength woods such as hickory and especially osage orange ( a wood favored by many Native American tribes for bow making ) . Good quality yew wood is still much more expensive and difficult to find than woods suitable for flatbows , and beginning bowyers are strongly recommended to start with a flatbow made from easily - available wood . Because yew , the wood of choice for European longbows , is light , resilient , and has exceptional compressive strength , the rounded design can be used to produce a smooth shooting , efficient , powerful bow . This is economical of wood and of the bowyer ' s time . Disadvantages of a rectangular cross - section . Compared to a narrow , rounded longbow design , the bowyer needs to start with a wider stave , take more time to achieve an approximately - rectangular cross - section , and may need to cut through growth rings on the back of the bow . Historic use . Flatbows were used by Native American tribes such as the Hupa , Karok , and Wampanoag , prehistoric ancient Europeans , some Inuit tribes , Finno - Ugric nations and a number of other pre - gunpowder societies for hunting and warfare because , unlike longbows , good flatbows can be made from a wide variety of timbers . Flatbows fell from favour in Europe after the Mesolithic , replaced with yew longbows . The trade of yew wood for English longbow s was such that it depleted the stocks of yew over a huge area . Flatbows are currently used by the paleolithic Sentinelese tribes of the Andaman Islands . Flatbow survived in cold areas , such as Finland , where yew does not grow naturally due to climate . The traditional Finnish flatbow is made either from ash , or as birch / pine laminate glued together with fish or hide glue . The yew was known as an imported material for bows in Finland , but it was considered not suitable for serious use , because it is fragile in cold temperatures and the season for hunting for furs is in January and February , when the furs are at their best . American flatbow . The American Flatbow ( AFB ) , also known as the American longbow , was developed in the 1930s . It resulted from scientific investigation into the best cross - sectional shape for a bow limb . This research was expected to explain why the English longbow ' s D - section was superior to all other extant designs . Instead , it showed that the best cross - section was a simple rectangle . The AFB was developed by applying these research findings to the English longbow . The result was a more efficient and stable bow which can be made from more common woods . Because of its coincidental resemblance to some native North American bows , the AFB is also known as the " semi - Indian " bow . The AFB was popularised by Howard Hill and quickly displaced the English longbow as the preferred bow for target shooting . The modern Olympic - style recurve bow is a development of the AFB , usually using rather than wood , fiberglass for the backing and belly of the recurved limbs , artificial materials such as carbon for the core , with a built - up riser ( handle ) section of ( often made of metal , but other materials such as wood or phenolic have been used ) . While the tips are superficially like those of the traditional Asiatic composite bow , they are flexible rather than static as described in Fred Bear ' s patent ( # 2 , 665 , 678 ) for bows with working limb tips ( recurve ) .