If it is not lace, the chances are it is a "skin" base - i.e. a very fine plastic membrane. Skin bases can look very good - it actually mimics a human scalp better than lace, but the hairlines are not as good. Whereas lace can actually completely disappear if it is attached correctly, with skin there is always a line at the edge of the piece which is visible on close inspection. So in my view skin based hairpieces are not suitable if you want to wear a style which exposes your hairline to full view. If you are OK with a concealed hairline, they are fine.