I think I might do that, as I might want to alter the colours.
I like things in negative, and psychedelic colours. It'd be cool to alter a picture with your thread for either of those effects. Or even a sepia tint but that might be very difficult.
I've never seen the back thing on its own though. =/
Do you do it on a cloth or with those squared materials? >_< I don't know the terms. But I know my aunty and her daughters used to do it a lot and they just did it on plain cloth with a pattern which looks really hard. I'd probably not do the x's the same size at this level. lol
But I've not seen the square material thing plain and for sale. o.o
I'd be interested to see how much sense I just made with that. haha