Let me start out saying that I am new to printing Ilfochrome and this is the only color process I have used. Last night I printed a few nice 8x10s of this one scene. I got the colors just where I wanted them and the exposure just right. I decided that this image would look beter as a panorama so i decided to open a new box of 16x20 and cut it down to 8x20. Since this was a new box of paper I cut one sheet into 4 8x10s and one of those into 4 4x5s. I calculated the diferences in filtration and setup the enlarger. I made a few 4x5s and determined the new filtration was just right (I was amazed as this was the first time I had done this). I then made two new 8x10s on this same paper and found that they closely matched the old paper. By then I had run out of chemicals and it was late. So this morning I mixed up a new batch of chemicals and reframed the image to the 8x20 size. I made a 4x5 and 8x10 test image and found that everything was still working, so I cut a 16x20 sheet in half and exposed both halves. I ran these through the processor (Jobo) and when I pulled them out they were horrible. The whole image had gone magenta. I made another 4x5 test image and it again turned out fine, so I figured I had contaminated the drum. After washing everything out I tried again. Same result - mageneta. I then figured I had somehow ruined the batch of chemicals so I put them aside and mixed up another batch. And tried again with the same mageneta results. Finally my wife suggested that I try an old sheet of paper with the old filtration and a new sheet at the new filtration. I did this with an freshly cut down sheet of 16x20 and an older 8x10. The old sheet came out fine, but the new sheet was still magenta. If you are still reading this, thank you. The only thing I can come up with is that the first sheet in the 16x20 pack, which I cut up for test strips, was different from the subsequent sheets. Has anyone else had this problem? Do you have any ideas of what else could have caused this? I figure I have wasted about $40 worth of paper and chmeicals today, along with a bunch of time - what a true waste of a day.