While I'm in a combative mood, let me tell you about "trace-down paper", as advertised, along with a lot of other completely useless stuff, on a website I shan't name..... I've just part-watched a video by a well-known tv artist (part-watched because I rapidly ran out of patience) who starts his demo by telling us that one of the most difficult things to do in watercolour painting is to get the image down on the watercolour paper. Er, why? If you can do the drawing on a sheet of cartridge paper, why, exactly, can't you do it straight to the watercolour paper? And anyway, you don't NEED a very tightly detailed drawing on watercolour paper - but let us leave that and move on to stage two. Terry, whoops, I mean he, also tells us that the way to transfer a drawing from cartridge paper to the watercolour paper is to buy a product called trace-down paper..... why on earth and in God's name would you want to do this??? All you need to do, if you're not confident about transferring an image from cartridge to w/colour paper, is to coat the back of your drawing with graphite, ie any soft pencil you like, and trace it through: "trace-down" paper, also known as carbon paper, was useful for typists when I was running an office 20 years ago, but has no conceivable use now, unless, of course, you want to make money out of amateur artists. It is USELESS: or if it isn't, you can do just the same job with a soft pencil.... I struggle to convince myself that these people mean well, though I suppose they do; I am prepared (generously) to concede that a sheet of trace-down paper will possibly work a little better than a perfectly ordinary sheet of cartridge with a coating of soft graphite on the back; but for goodness sake, are they TRYING to part people from their money? You don't need it. It's completely unnecessary. Don't waste your money, which you could much more profitably spend on good quality pencils, best quality paint, and receptive papers or canvas. I know I shall make enemies here, but do you know - I don't care. I see no reason in the world why artists should be cajoled into spending money they don't need to spend; and am losing all respect for fellow artists who plug products for which they know there's no real need.