Flatbow

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.

The flatbow is a superior bow design for almost all materials because the stress is more evenly spread out than with rounded limb sections.

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 ensure that all of the most 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 resilience needed in a bow).

Suitable and easily available timbers include elm (used in ancient Europe, as evidenced by bows pulled from European bogs), maple, sycamore, hazel, and ash.

[citation needed] 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.

This kind of glue will never be all waterproof and the bows were most often wrapped with thin strips of birch bark, protecting them against weather and moisture.