Various - Wood, durasteel, chromium, etc.
A popular melee weapon, the dagger can be used to inflict flesh wounds on targets within close range. Small enough to be carried around in a humanoid sentient's hand or hands, the dagger is the preferable tool of mercenaries wishing to conceal the weapon within their clothing. When not being used for cutting and slashing, the dagger - depending on the skill level and experience of the user - may also be thrown at targets who are up to a meter away.
The dagger is legal to carry in most parts of the galaxy, except of course wherever it is not. Even then, in illegal territory, it can be easily hidden on one's person in order to conceal the fact that it is there.
Daggers can be used for self-defense, to attack one's targets, to carve from resources in the wilderness of various planets, or to catch wildlife to eat for food.