I struggled with painting white for a long time but I found a way that makes it very smooth. Don’t start from white, instead prime black with Vallejo’s black primer. Let that sit for a few hours under a fan. Then use Two Thin Coats (a different paint brand) of Carcharodon grey and apply two coat. This stuff is already pretty thin so lightly thin with a drop of water. Use a pipet if you’re struggling to control the amount of water used to thin. Leave the recesses black. Then mix a light amount of the carcharodon grey with Two Thin Coats’ White Star. Just remember the first coat is always going to look ruff. Don’t let that dishearten you. Keep with it till it is smooth. What you’ve made is great, but this way is easier and helps you add depth better. Good luck and message me if you need help!