This is a very inexpensive set of hollow stamps, the whole set costs less than some individual stamps from other sources. Because of this, I didn't expect them to be nicely designed (which they aren't). However, I expected them to be functional (which is not the case). These tools cannot even cut through cardboard or thick paper accurately. If you press very hard (which you don't have to) the edges will curl, making them even less functional. This is with a standard food cutting board behind cardboard to be perforated. If a plastic cutting board can round the edges like that, these tools are certainly not "heavy duty" as advertised.