Hardcover bookbinding quality should meet the following requirements.
(1) The book cover and the book cover are flat and flat. When the flat cover is placed, the middle diameter cardboard and the book block do not look at the gap. The four corners of the book are vertical.
Surface float width: 32 open and below is 3mm±0.5mm, 16 open is 3.5mm±0.5mm, 8 open and above is 4.0mm±
0.5mm.
(2) The back side of the square back is straight, the circular back is between 90° and 130°, the spine is straight and its height is consistent with the surface of the shell.
.
(3) The book slot is visually straight, with a width of 3.0mm-4.0mm.
(4) The gauze, ring lining and the inside surface of the book cover are firmly adherent, level and free of bubbles. Adhesive is used properly, uniform glue, no flowers
No spill.
(5) The book case ignoring the view curvature, the back of the book ignores the view skew.
(6) The appearance of the finished product is clean and free of dirt.
(7) The error of the upper back and forth of the full set of books is ≤ 2.5mm.