This is a DMC Needlework Threads Colour Chart. It has 6 double sided A4 pages that all fold out to one long page. Each colour has a sample of the thread with the number alongside and it lists what type of threads are available for each colour. All the colours are arranged in their shades i.e. All the blues are together, all the greens together etc. It has all the numbers & colours for 6 strand cotton embroidery floss, Pearl Cotton, Colour Variations and Light Effects. This would be excellent tool to help you chose colours when designing or amending a pattern. As it is arranged in the various shades it would help you to blend colours on your pattern as you can see what other numbers are similar shades.