I will have to do a write up with some photo's and such - but, here are my initial impressions of the Terraslate:
The paper has a pretty nice tooth to it, which you can feel when rubbing it between your fingers. Yupo in comparison, is much smoother feeling. My first test was o take some Com-art Transparent Smoke (remember Com-art here), and try some simple spray tests. Some lines, gradual shading, and some built up overlays of spray. The paint laid very nicely on the paper, and dried evenly. Just a few minutes after application I tried erasing, scratching, and hitting it with a wooden dowel - and was quite satisfied with all the results I got. After allowing the paint to dry for about half an hours, I got the idea to try some colored pencils on the paper, as like I mentioned earlier, it has a fairly nice feeling tooth to it. I was using Faber-Castell Albrecht Durer Watercolor Pencils. They actually lay down quite nicely on the paper, blend very well, and erase completely without damaging the papers surface. While I was at it, I decided to try layering the colored pencil on top of the sprayed areas I laid down earlier. Worked like a charm. On Yupo, the paint would have peeled or chipped as if I was using a wooden dowel.
After some time, I wanted to try a different effect so went back into the studio, and sprayed a few light layers of Com-art Chrome Green. Waited a little while, and tried a few different erasing techniques. Trouble came when I tried to layer over it again with another coat of Chrome Green. The paint lifted, or re-wetted. Instead of building layers, I was shooting back to white base - My fingers also started smudging the surrounding areas... I had none of this trouble with the transparent smoke I tried earlier.
So, I switched to Golden High Flow, and had no trouble at all with a few tests that I tried. No idea if it was just the Com-art chrome green, or if other Com-art colors might not be a good mix with the Terraslate... I ill do more testing with Golden colors tomorrow. Maybe some more with the com-art also, as I have a good collection of them now.