Support BladeForums! Paid memberships don't see ads! These are my first attempts at making San Mai billets as well as my first hidden tang knives. So as usual I'm flying on a wing and a prayer. The larger is a 15n20 jacket with 1084 core. The smaller is 1084 jacket with a 15n20 core. Pre heat treat I finished to a 220 grit then post heat treat and temper I brought them up to 600 grit with gator belts on my grinder. They both were etched in 4:1 ferric for two 2 minute cycles then sprayed with windex. I rubbed them with my fingers and a paper towel. This is where I am currently at. Now how do I get the 15n20 to pop? I've read many threads where people state they pull it out the etch, windex it and done. I also have read with Damascus, most will lightly sand or polish only hitting the 15n20 layers as they were less effected by the etch. What's the next step in my case? Buff? Hand polish ? Polish only the 15n20 ? Read more, reread until I understand because it's been asked and answered too many times before ?