Thanks for responding, Damo. The photos (fun shots- b&w advertising style from my teenagers birthday party) are being printed, emailed etc by a multitude of teenage party guests. Just wanted to have a reasonable chance of them looking the way I intended ( looking at them in my color controlled environment ). I ended up keeping them as RGB (sRGB profile) images after dropping the saturation all the way down in Capture One, where I had done the captures tethered to my computer. This was easy and looked fine. The file sizes are bigger than they would have been if I had actually converted them to grayscale though. But leaving them RGB with the sRGB profile ended up seeming like the safest, most universal way to go.