I just did an install on some windows using Sihl value line 3215 80/20 perf and when you look at it from certain angles you can see marks in different areas. This is my first time using this material but is that common with this material or is there something I should have done differently on this? I have used other perf before and didn't have this problem so I wasn't sure if it is just more noticeable because it is a solid black color or what I should do to prevent this.