Sofas generally come with one of two types of backs. A Pillow Back,
which has removable cushions or pillows along the back and a Tight Back,
in which the upholstery is tailored to the contours of the Sofa’s back.
Pillow Back Sofas are considered more casual, comfortable and inviting.
Tight Back Sofas are more tailored and can have a formal look to them.