I have 3 boat loads of the Cranes 90lb natural white. About 800 sheets 11x14 direct from Bostick and Sullivan that I inherited and another quite large batch I bought from a paper supply house in the 1990s and then a bunch of full sheets I bought from Photo Formulary maybe a year and half ago. None of them have black specks but the 800 sheets tends to mottle more. If you look through the paper at a bright light so you can see the paper fibers, there is a huge difference between the 3 batches. One being quite clumpy and another being spidery fine and one half way between. But the point is not to expect any paper to always stay the same.