Does anyone know how to slove my problem ? I developed several sheets of 11x14 film (HP 5+) with PMK pyro in the Jobo 2834 paper drum which holds one sheet of 11x14 and found that clear vertical lines (t hinner stain than the other) on the negative. After printing those lines are clearly visible and ruin the image. That never happen with the Expert drums for my 8x10 negatives. There are 12 protrusion lines inside the 2834. They contact with film and make t hinner lines. I use a split developer solution and EDTA addictive.