So I'll be quick.If your tattoo stencil misses a couple of spots or it's large or you just want extra security in regards to not losing any markings these are amazing.I had to use two cause one got lighter cause my skin still has transfer cream on it so it got on the pen but other then that they're perfect. If you don't TRY to take the ink off it'll last about 2 ish days. They really helped on a tricky stencil I was doing on my bicep and honestly I ended up redrawing most of the stencil with this instead. In my opinion nothing is worse then working on a stencil then I botch it up when applying and these have removed that problem from my amateur tarping completely. Plus since it's only used on me I opened 2 for now and saved the other 4 for a rainy day or for someone else. With every penny and then some and highly recommend if your starting out and haven't mastered a clean stencil pull yet.