If be of timberwork cloth art sofa, part of main body frame uses structure of mortise and tenon commonly, if discover those who assemble to in-house frame is nail completely, cannot buy absolutely.

• 假如是木结构的布艺沙发，主体框架部分一般采用卯榫结构，若是发现内部框架全是钉子组装成的，绝不能购买。