The preferred method of application is spray gun. Using a roller always ends up with a coarser finished product since the stickiness of the product leaves a higher profile texture. Also… it is difficult to get the high build with a roller since the thicker the application, the coarser the texture. Since you would have to apply additional thin coats, you would have to allow the first coat to almost cure in order to not dislodge it an cause a mess.