I use cotton fabrics too - that is all I own - just my preference. I use either cardboard and cover it or found some foam core board from Walmart and used that too. Problem I am noticing is the bottom board tends to work its way up while using the bow tuck purse - does anyone else have this problem? and what did you do to fix it. I am thinking I need to put velcro on the covered mat at the bottom of the purse to keep it intact - otherwise it gathers all my change and etc then it starts working its way to the top. Hope I haven't confused you - these are really fun to make and everybody loves them...