Butter Knife
Best Butter Knives
Butter knives tend to have a round point, so that they do not tear the bread. They very often have a sabre-esque shape. Generally each guest would have one butter knife each.
Alternatively, a master butter knives is not used to spread the butter onto bread. They are primarily used to allow diners to get butter from a central butter dish on a table to individual diners plates. Otherwise this would potentially contaminate the butter remaining in the butter dish when the next diner gets some.
Rather, diners at table use an individual butter knife to apply butter to their bread.