Yes, they do. I use the Fender Nylon Tapewound 9120's everyday on my fretless Fender J bass. Tapewound strings have metal underneath the tape. In the case of the 9120's they are a roundwound string simply wrapped in black nylon.
It's not a stupid question. I wondered the same thing about them before I tried them years ago mainly because I didn't know how they were constructed or what materials they were made of.
