The model prints as is with no need of rafts or supports. There are 9 layers but start from smallest and you can stop at any point if you would rather have the usual 6 color rainbow. 

They slide a bit so works best on carpet but you can put a couple dots/strips of hot glue on the bottom of the arches to give them a bit more grip just be careful cause the heat can warp the plastic. 

ENJOY!