Should I size up or down because it is raw denim?
This ultimately comes down to preference. Raw denim will stretch about an inch in the waist and all over with everyday wear, so some people size down to accommodate for this. If you do this, you will need to understand that the jeans will fit snugly when you first put them on and then they will fit more comfortably once they stretch out. Other customers buy true to size without sizing down and then wear a belt once the jean stretches out to avoid the break-in process. This comes down to your preference!