More Important tips you need to know when you apply the contact paper:
The First, please clean the wall thoroughly before you put on the wallpaper.
The Second, dusty walls don't fit with wallpaper.
The Third, you can use a soft scraper or towel to scrape off excess air bubbles.
The Fourth, If there are air bubbles after pasting, you can pierce the bubbles with a needle or a knife, then use a towel to push the air out of the air bubbles. Then it will work great.
