Leather
Welcome to the forums.
If you run a search under survival knives, or, hollow handled knives you will pull up a number of threads.
Many of us were burned during the survival knife craze of the 1980s. We have found that these knives suffer from three serious limitations.
1) The hollow handle storage space is virtually useless. When these knives first evolved during the 1930s the space was simply intended as a matchsafe. During the 1960s Randall and other makers came up with larger knives to carry survival supplies, but these supplies were largely envisioned as pain killers, stimulants, and the like. It was only during the 1980s, after the Rambo movies that the concept of storing all forms of garbage became popular.
Most of the stuff can better be carried elsewhere in your kit. By going with a hollow handle the blade tang needs to be significantly shortened. This makes it harder to produce a solid knife, and to many low-end makers never even tried, so many of these knives tend to break at the blade/handle junction.
2) Many of these knives tend to come with sawbacks. These
sawbacks are generally completely useless, and even the best of them are best suited for very specific purposes such as cutting through a helicopter canopy. Even though they may be cool to look at they are a constant wear point on sheaths and produce serious stress riser. I have seen some very good survival knives such as the Randall model 18, the Buck 184, and the Parrish Attack Survival, broken at the sawback. These are excellent knives, but the sawback feature limits the amount of prying that can safely be done with the blade.
3) These knives tend to be heavy and awkward. The metal pipe
handle provides very poor indexing and simply does not fit the hand well. It is not very pleasant to take hold of a metal handled knife in the cold or on a hot day. Cord wrapped handles may be cool but they are used in a crude attempt to make these handles a little more comfortable.
N2S