Unlike other printer paper containing a fraction of recycled paper, the supposedly "99.99% jam-free" Great White 30 paper I received JAMS almost invariably during two sided printing (Samsung ML2850 laser), with the sheet jammed half way out after the page side flipping. The printer receives proper maintenance and cleaning of its rolling parts, and other brands of printer paper placed on its tray do not cause jamming. I sampled the three 500-sheet reams included in the box --which have the same batch code and sequential time stamps-- and sheets from all three reams cause the problem.
Further, rather than Great White ought to be called Great Yellowish White. The attached image compares one sheet of this product (left side) against one sheet of another brand of nearly the same price (Office 20 HP, right side) placed on a black surface, illuminated with light from a north-facing window slightly past noon -- the Hammermill sheet clearly looks more yellowish than the other sheet.