Hardback

 Hardback （hardback shade)灯具中指平贴灯罩，一般是布罩

Hardback means "A stiff backing applied to the inner surface of a lamp shade to keep its shape over time. During the creation of a hardback lampshade, the fabric is laminated over a stiff but bendable backing material, typically a plastic such as a styrene. The hard backing helps the shade to keep its form, prevents drooping or warping, and extends the life of the shade. With a hardback shade it often becomes unnecessary to use extra metal framework running between the top and bottom of the shade, since the backing maintains the shape. This removes the shadows or blocks to light caused by the presence of vertical framework showing through the shade".

Hardback drum shade

Hardback drum shade