These soles were meant for bowling shoes, so they are smooth. I purchased sheets of this soling from www.repurposedmaterialsinc.com. Since it is “repurposed” I consider it ecological. These soles can be stitched to the uppers if you make a groove in them for the stitches. They can also be attached to the uppers with Barge or other shoe cement.
If you plan to use shoe cement to attach any rubber sole to the upper, your topsole will bond to the bottom sole best if you use this sole as a midsole. The shoe cement bonds the best when you adhere rubber-to-rubber. When making the shoe you would cement the topsole to the midsole, then stitch this two-layer sole to the upper. Lastly, you would adhere the midsole of the shoe to the bottom sole.