Oh, this takes me to the "wayback machine". So, the original market for Ektamatic SC - it was used for rapid printing of B&W for press work in newspapers prior to RC papers coming out. Kodak made a companion processor and chemicals that made a print available in less than 30 seconds to be viewed. I printed on this stuff a lot in my job back in 70s using the processor. It made a damp sticky type print that air dried sort of. If you wanted to keep the print long term you just fixed and washed as normal papers. As I recall the paper was very similar to the Polycontrast Rapid fiber based paper without the rapid processing. The A weight paper was able to take pencil or other retouching materials very easily. It was half the thickness of single weight and as you determined the 8.5x11 size was great for contact sheets.