I have spent the last few days in the darkroom dealing with a serious issue with Ilford Multigrade FB. I was working on a negative that I was split filtering, that is using a combination of 130m filtration (grade 5) and 130 Y (grade 00), the image itself needed to be printed high in contrast as it was being diffused. I was getting an unusual amount of texture in the sky, a grittiness, which was strange considering I was using a 4x5 Tmax 100 neg. I thought that maybe my paper was fogged, so I tried it on another batch of Ilford Multi, and had the same effect, I tried it on a piece from a new box of 20x24" paper and the problem seemed far less evident. Today I went to B&H and bought 3 different batches of Ilford multi in 2 different sizes. I am still having the same problem with the brand new paper. The problem only appears when the higher contrast settings are used so i decided to do a test. I covered the enlarger lens with a translucent diffuser, the kind that they use on light boxes, no texture will be projected this way. I turned off all the safelights except one, a Zone vi LED safelight set for VC paper and quite far away from where I was working. I exposed sheets of Ilford Mutligrade under the heavily diffused enlarger, the filtration set to 130m, even making it a point to actually move the paper continually in large sweeping, random motions during the 1 minute exposure to insure that no texture can be projected on the paper. After processing and fixing what I ended up with every time was a zone 4 print with an extremely visible, random texture, which can be best described as a coarse sprayed effect with a slight bit of uni directional run added. I tried this on some really old Oriental VC paper, at least 3 years old, paper that I new had to be way fogged and it had a similar but clearly different mottling, not as bad in fact as the brand new Ilford. I have a huge amount of printing to do over the next few months and am at a loss for this problem. I have used this same printing technique in the past and never had problems using grade 4 or 5. I well be getting other brands of paper this weekend to see if the same problem can be duplicated and to hopefully find a paper that allows me to use grade 4 and 5. Anybody ever experience anything like this? Is it possible that this is a result of the paper being x-rayed on it's way to B&H? Is it possibly and uneveness in the coating of the high contrast layer?