Sorry it has taken me so long to reply to the questions. It was inspired by Penny Halgren's
http://www.youtube.com/watch?v=FgfzxzwTzro tutorial and also by racerh with her lovely quilt.I started off with an 8 inch triangle but found that to get the effect of the cubes escaping the quilt would have ended up about 20 ft long.I remade the large bottom cube using a 7 inch triangle and then made smaller ones each time.The very small hollow cubes start with 1 inch triangles . They were a bit of a fiddle but I managed to do them.The small solid cubes are raw edge . I used batiks and painted the edges with fray stopper.The cubes within the cubes are appliqued too.I used several different methods to secure them.some have the edges turned under and I used invisible thread, by hand and by machine. I used Bonda-web( wonder- under). I think it's called in the US .I hope this helps. It really wasn't hard to do . Oh ,I forgot to say ,on a couple of the cubes where the inner cube didn't fit very well I just opened up the seam of the outer cube and tucked the smaller inner one inside.Thank you for all the lovely comments. I very much appreciate your replies.