It depends on the brand. The ground up pigment in French Ultramarine is supposed to be larger but I don't think there's really isn't a set particle size to define the split between the 2.I heard that French Utramarine blue was warmer than Ultramarine blue - so far I'm not seeing it - looks identical to my eye.
I'm not Kay but I think I can answer your question because I do have those. They're not blocks. They're in a pan like our western watercolors but they're very big pans, about twice the size of one of the western full pans. I've never seen or tried Derwent but I think they're different.Kay, I hope you enjoy those blocks--oh, are they pans? I've wanted a set of the Derwent blocks for years. Maybe I'll get me one soon. I wonder, can you pick those up and use as a block, like a crayon? They are less expensive than the Derwent.
Angela, what were the new neocolor II 's that you got? Are you enjoying them? I never did get more, but still think I want a few.
RW, your work is wonderful, even without the new tools, so these will allow further enhancement. Have fun!
Amazon has the best price, 60" x 150' = $56I need to pick up some glassine as well... in a roll at least 48" wide. This would allow me to stack my pastels as opposed to rolling them. I did this for years but ran out of glassine a number of years ago.