Good Question! That was exactly my thoughts! I watched multiple videos and all of them say that acrylic paint straight from tube is perfectly fine. I also washed those jeans inside out on cold and air dried them and they were perfectly fine. I also tested few different techniques previously, including involving medium. Please check link below : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-EVdcUDzOWNw.htmlsi=yW8HLESw5WZHF3N0 I hope that helps! ❤
