What does the red spell protect?

In the past, red paper was mainly used to write couplets, or to put a red note as a seal on gifts for others. Sticking red paper and seals on the door is actually a blessing and evil spirits.

In addition, people can also see small pieces of paper cut from red paper and pasted on the bedside, door, car or pigsty door, all of which are used to pray for peace.