Is the hair really natural looking if you have poly on top? I plan on having a part in the center of my unit and want it to be undetectable. I currently have a lace unit with poly on the sides and the hair injected into the poly doesn't really look quiet natural the way it is inserted into the poly. Can any poly wearers enlighten me?

The reason I am asking is because I currently still have some hair growing on top that is very thin, but very dark. So after a few days my natural hair is showing under the lace and making the lace really stand out. I was hoping to that switching to poly might solve that problem for me.