I've long known that divided development does not work well for resin-coated papers. The emulsion is just not absorbent enough to retain enough developing agents from Bath A to be activated by the activating agent in Bath B. Semi-matte surface RC papers do better than glossy, but none do well. In areas where there is a large expanse of dark tones, they tend to be washed out and gray.

A few months ago, I bought a box of Polymax Fine Art Fiber base to use for contact printing, since it is the only paper to knowledge that comes in single weight. I hate using premium double-weight papers for contact sheets.

It acts, in my divided developer, exactly like an RC paper rather than a fiber-based paper. To get good blacks in my contacts, I have to use a single-solution developer.

I'm wondering if Kodak incorporates some resin into their emulsion even on a fiber-base paper.