The main reason is that the completion time of the signboard is not fixed. For good luck, merchants must choose a good day to open a signboard, but the signboard must be hung up first. So, first cover it with red paper or red cloth, then open it on a good day and set off firecrackers to celebrate. This is the official opening! ! ! ! Unveiling the red cloth is also a ceremony at the opening ceremony, just like cutting the ribbon to unveil the bride's red veil!
There is also a saying that it is related to taxation. It seems that Mengbu is a trial operation agent, and it costs less.