The horn bow is made of several types of materials. The belly is made from waterbuffalo horn, the core is bamboo, the 'ears' are of acacia or mulberry, the handle of oak; it is backed with sinew, that is covered with birch bark, with everything being held together with fish air bladder glue.
The laminated bow is made from different materials, too. The belly is made from a special material the Koreans call 'black paper pulp'; it simulates the horn on the horn bow and is quite durable. The inner laminations are of either maple or bamboo (depending on the model), carbon, and a couple glass layers. The 'ears' are made of acacia, just like the horn bow and the back is covered with birch bark, also like the horn bow.
In Korean archery, we brace the bow with a step-through that is a bit different from the 'western' style. First, put the string loop around the upper limb's nock and hold it in place by pressing it against the bridge pad (making sure it isn't twisted and the loop fits on either side of the 'ridge'). Next, with the belly facing outwards, place the back of the lower limb above the left knee and the right leg over the bow, so the back of the right knee is against the belly. Next, flex the bow, so you can place the string on the lower nock. When placing the string on the lower nock, twist (rotate) the string to the left (CCW, as you're looking at it) several times and place the loop on the nock, untwisting it as you did with the upper nock. Let up carefully, being certain the string is seated correctly on each nock.
Now, draw the bow back and look at the string loop, seeing how it lifts off the bow. If it turns at all, it needs to be twisted more, on the lower limb, just like you did before placing the loop on the nock. When you have a turn in the loop, it means the twist is off; it will tend to make your shots go a bit off, too, so you need to get it corrected.