I gave this 4 stars because the quality is excellent. Mat is thick, magnets strong, the lines and measurements are very helpful. I'm not sure that I need this product, as I don't really feel the need to lay things out, pin them into place with the magnets, and then hold the mat up to look at it? However, there may be occasions when that is helpful. I've used the lines a bit, and as I get used to it, I think I will use them in more ways. The black color makes working with a dark background paper difficult.