There are several different types of Copics. Most people use either sketch or Ciao (there is also original and wide). I got the Ciaos because they are so much cheaper. The sketch and Ciao are exactly the same marker, except the sketch holds more ink and is an oval shape (ciao is round). Sketch has more colors available too. Some people also like that the sketch markers have the number on the top, whereas the ciao doesn't. They say you can't airbrush with the ciao, but there is a video on youtube showing that all you have to do is put some foam dots in the air brush thingy to make the ciaos fit. The Sketch markers run around $6, and the ciao markers go for around $3-$4. According to the
FAQ's on the Copic marker website the sketch markers hold 2-3cc's of ink and ciao markers hold 2cc's. So going by that, sketch markers only hold about half again more ink at the most, but the price on the sketch is about twice as much, so I felt that the ciao markers were a much better value. Copic markers are wonderful! I don't think I will ever color with anything else. I absolutely love mine! I wish I had got them years ago! They are also refillable and you can even replace the tips, so they are a lifetime marker. Like Lori said, there are tons of great threads about Copics in the tool and product forum, so you can find lots of great info there. Oh, also check out Ilikemarkers.blogspot.com Marianne works for copic marker and has just about everything you'd ever need to know on her blog.