Use the cutting tool to cut at an inverted 45-degree angle.
Generally, it is laborious to cut corner window lines, especially if they are uneven. If you have professional cutting tools and skills at home, you can start work after confirming the length and cutting strength. If you don’t have professional tools, As well as professional skills, be sure not to try it yourself to avoid consequences such as cutting corners too deep and breaking the window sill. Just go to a professional carpenter or professional decorator to handle it.
Note: Before cutting the door frame line, you must first check whether there is any foreign matter in the slot. If there is any foreign matter, it must be cleaned. However, the strength must be controlled during the cleaning process, otherwise the corners of the notch will be easily damaged.