Thanks for looking!
The texture comes from the art paper. It's a high end paper used as art material and as a supply in the floral industry.
They're sealed with a clear, matte acrylic sealer. They're water-resistant, but I recommend gentle care. I've worn my prototype tons, and it's very resilient. I wouldn't recommend putting them on outerwear in extreme climates for daily use, however (heavy rain, wind, snow, etc.).