There are different grades and densities of "Sintra" The stuff I am used to using sands just fine on the edges and is wonderful to work with. I recently got with a local plastics supplier for sign companies and picked up a 4x8 sheet of the same stuff, but another brand and it's noticibly softer and has more porous edges like Division 6 mentioned. Expanded closed cell poly vinyl chloride "Sintra" will dent and gouge easier than styrene too, so if the item is going to be handled a lot, like at conventions and such, it may get beat up easier. A lot of prop makers like using Sintra for their master that they will be molding because it is so easy to work with. Styrene is a little harder to cut and thicker sheets don't bend as easy, but it's generally more durable. I hope this helps !