While using guillotine why do victims cut their hair?

Answer 1

The French physician Joseph-Ignace Guillotin was associated with the machine made famous during the French Revolutionbecause of his efforts to convince the French National Assembly to adopt some sort of new machine as a more humane method of capital punishment.

In the interest of a more humane way to kill people, the machine was boasted as the quickest, most painless way to to do this. Long hair would cover the neck and could interfere with the blade, meaning that they might not have a clean slice the first time, and would have to raise the blade again and again until the head came off. In fact, rich people would pay the executioner extra to make sure the blade was sharpened.

Of course, chopping off the hair had the added benefit of disgracing the criminal immediately before death.