You see a lot of paper debris in the air that looks similar to the striated but crumbly paper in the OP video. You make a good point and I think it's both thin

You see a lot of paper debris in the air that looks similar to the striated but crumbly paper in the OP video. You make a good point and I think it's both things, actually. 1) The bonds in the paper fracture 2) The elastic energy in the press causes the cylinder to drive downward, splattering the malformed paper in all directions 3) Which makes room for the cylinder to make it most of the way through the book.