pretty much every vein in my arms show, I have a couple running on my bicepts, they show right now even though I'm in a bulking phase and about 15-20lbs heavier than when I lean for summer, I think it has more to do with how vascular(how many veins you have, how large they are) you are than anything else. Even the veins in my chest and legs show, and when I'm lifting all of my veins really show. I think the more you lift the more you are going to see your veins