Much more than just a catalogue. Yes, all the colours shown in one easy to use catalogue, but additionally: compatibility information, firing guidance, mould, supplies, and most useful of all - a big matrix showing which colours and types of glass are available in which styles (sheet, frit, stringer etc). So, for example, it clearly shows that you cannot get stringer in mineral green but you can get stringer in in teal green. A real time saver compared to searching for things on the web, and very helpful. Additionally a little bit of interesting background reading and other stuff. I find this a useful and convenient complement to the Warm Glass website.