There is a bewildering variety of high quality folding knives for sale. Gerber lists over 80 different models of folding knives on their website.
This article will help make sense of the variety.
It is important to check local laws. For example, United Kingdom law allows only non-locking knives less than three inches long to be carried (Spyderco designed their "UK Pen" model specifically to comply with UK law).
Common restrictions include
Restrictions on where knives can be carried (example: banks, liquor stores, schools, work places) should also be noted.
Blades should lock when open. Otherwise the knife could accidentally close on the user's hand. An injury like this when backpacking in a remote area would be dangerous.
Blades should also lock automatically on being opened. If a separate step is required to engage the lock, the step can be accidentally skipped.
Blade length will affect the usability of the knife more than any other feature. Shorter blades are easier to control but may be too short for some tasks.
Knives with serrated (saw tooth or wavy) edges
Unless there is a specific requirement for a serrated blade, a plain smooth edged blade is the safer choice.
A good non-slip grip is essential for safety. A slippery handle can cause the hand to slide up onto the blade.
A good grip comes from
Not many people will be willing to use a knife costing hundreds of dollars for rough work.
A more modest knife will be more likely to be actually used. Two knives can be purchased instead of one expensive knife:
Modern folding knives have holes or studs in the blade so that they can be pushed open with the thumb - opening the knife using only one hand.
This is a safety feature, not a gimmick. In an emergency, one hand may be occupied (holding on to something) or injured.
While a small detail, a hole to allow a carrying cord to be attached is useful. It can prevent the knife from being lost. The cord can be clipped to the belt or the backpack.
A knife from a well-known manufacturer will be fine for general use. Super steels with names such as ATS-34, ZDP-189, VG-10, CPM-S30V are nice but not necessary.
While there are many different models of folding knives, the main features are not complicated. Safety and usability are the main concerns when choosing a pocketknife.