When the wall and ceiling are made of different materials or colors, there will be a clear dividing line. It also plays a decorative role to cover this boundary with internal corner lines and choose wood lines or plaster lines according to different indoor styles.

1, the application in architecture

The yinjiao line in the book has functional requirements. With more and more minimalist trends, non-functional feet are simplified and cancelled.

2. Application requirements

Some interior designs abandon the inner corner line, even if the color difference between the wall and the top is great, they would rather leave a boundary line, but the line should be straight.