How do I make a sculpture with foam core?

Is it fine to use a ruler instead of foam core for paper mache?

• I need to make a paper mache katana for a school project and I was wondering if I could use a ruler as a base instead of foam core/cardboard etc. Thank you in advance

• Answer:

  Doesn't seem to be comparable - a ruler is a thin, shiny, narrow piece of wood and foam core is a thicker paper over foam art material that comes in sheets. I suppose you could make a support out of a narrow blade like material but any reasonable sized doll would fall over.