Before sticking the wall covering, it is necessary to brush special glue on the wall where putty is scraped to increase the firmness of putty.
When pasting wall covering, the amount of glue is also regulated, so it can't be pasted and peeled off repeatedly, otherwise it will easily cause putty to fall off.
As for the problem of air bubbles, it is caused by poor pasting technology. This is a technology, which needs to learn operation skills and practice operation methods, and it is impossible to do it overnight.