I don't wear a full cap, but I don't see how the base could ever be undetectable to the touch in the area below the skull (below the occipital ridge). If you can use your biohair in that area and have the wig end at the edge of your skull, that is bound to be a better solution. Have you enough real hair to do that? Remember, your real hair will be bulked out with hair coming down from your piece.