Hello to everyone.
I’m struggling with the upper part of a slipper like this http://www.handballcompany.de/1446-thickbox_default/hummel-pool-slipper-velcro-schwarz.jpg
I want it to be a single layer of material with 2mm thickness that goes all around the slipper (it has an hole in the midsole)
I quickly created a curve that does that but I’m can’t create a surface from that and give the 2mm thickness. Probably I’m approaching to it the wrong way. (Also how can I be sure that the two flaps will coincide? I’m not sure I explained myself, I mean the parts that will be connected with velcro)
please help me! 
