Hardcover Book Printing
Normally ,2-3mm thickness of cardboard, and 160gsm offset paper for ends. Square or round spine.
Hard cover make the books looks like more luxury.
Due to sewn binding, the books could be open flat.
For book store, long time for holding is an advantage.
More functions of hardcover book printing
Many cookbook are bounded into hardcover books, to make the books looks more luxury.
Highlighted photoes could be decoratived. Also the inner pages could be open flat.
For the education books, a strong cover is more important to the final clients.