I Thought this would be a good project for my 6th grade class and wanted something more professional than the easy stuff you can take off with a finger nail. I wanted them to be able to use tools to have varying line weights & textures. The packs I got seemed very brittle and you could barely scratch off the ink without tearing the sheet. Good news is I called and asked what I was doing wrong and they sent me back new packages that worked perfect! Thanks for the great customer service!