I’m not that picky about these. As long as the color of the paper is correct, the paper is acid free (doesn’t yellow) and it is smooth and thicker than regular copy paper (80g/m²). Especially with sketchbooks you don’t want the black bleed through the pages below. And when scanning the sketches to the computer, I hate when the sketch on the other page “shows” through the paper.
Paper
I do use regular copy papers for sketching too, quite a lot even, but on individual sheets. And even then I aim to buy paper between 90g/m²-100g/m² in thickness. These are also the most cost effective way to draw, you can find awesome discounts on bookstores or online office supply stores for various copy paper. I think the regular price for 100 sheets of A4 80g/m² is around five euros. Or is at least in Finland. If you are more into drawing on individual sheets of paper, and draw a lot with the intention of saving them all, I recommend paying attention to archiving. In other words, get yourself a good folder… or two. I won’t be reviewing these, because there are so many brands on the market yet the quality is – thanks to standards system – pretty much the same. Like said, the color (bright white) and thickness (90g/m²-100g/m²) are the only things you need to take in consideration.
Sketchbooks
I don’t want to invest too much on a sketchbook, for me 15 euros is a definite max. I gotta say that many of the sketchbooks feel identical anyway and the main difference seems to be on the cover material (and what’s printed on them) and the first interior pages. I wouldn’t be surprised if 90% of the books are manufactured somewhere in China, in the same factory even.
Pay attention: you’ll save money and nerves with good paper. Even the less good markers work actually pretty smoothly on a quality paper. And the opposite, shitty paper wears out the marker nibs faster and some inks might look more dark grey than actual black. On a good, coated white paper many of the markers I’ve rated to be closer to dark grey than black are actually solid black.
You’ll find the actual reviews here.