I suppose it depends on what kind of sketches you’re looking to get. For bigger, more elaborate stuff, I like a thick, spiral bound sketchbook with a heavyweight paper. The spiral keeps the pages from getting too beat up, and allows you to present the book open, and in the exact page you want the piece.

But if we’re talking about smaller, quicker pieces (usually like a simple headshot or bust), I keep a simple, perfect bound sketchbook in my bag at cons and events. Those work pretty well as most artists aren’t looking to get super in depth but can easily fill-up about 1/3 or less of the page with something fun, which tends to look/feel bigger in the smaller book. And they’re easier to flip through, so splurge and get a couple really nice pieces right up front (mine has a beautifully rendered Tom Strong by Chris Sprouse) where future artists will see them, and do their best to put the same kind of effort into what’s, effectively, the simplest drawing they’ll do all day.

Michael’s and places like that usually have them all for sale in the $6-19 range.

And if you’re looking for something a little nicer, there’s also Moleskine notebooks which I’ve enjoyed for years, and those have some nice variety to chose from.