Alright, I got ahead of my self....Ilford fiber base papers have 2 different chemistries, and choice of 3 surfaces....you are right, Fiber base now only comes in double weight. (which is fine by me, considering I will wash my prints for up to 12 hours or more, and sometimes multiple times). They do have 2 different double weights though, but ther is not that much difference between the two. Ilford RC papers have a choice of 3 chemistries, and 5 surfaces that i mentioned earlier. Fiber base is better as far as permanence is concerned.