A look at photographs at flickr a lot and some of them really amaze me. Today i found a really sweet one. A bookcase with rainbow colors.
I haven’t seen so much creativity in a “simple” bookcase 
Some people also consider ordering them in those blocks from small to big. Another thing is if someone wants a bookcase like this, he needs lot’s of colored ones. So some may have to buy some shades of colors so they can fill up the colored blocks. So it’s time consuming and costs money. But it think it’s worth it in the end.
If i’d had so much books i’d order them the same way, they just look happy there
