How to get rid of tape lines?

i am going to be painting my pyramid (i recreated the transamerica pyramid out of cardboard) so i used TONS of tape to keep it together. before i paint it, how do i get rid of the tape lines? please help! URGENT! no clay, no primer, and i'm not taking the tape off because the whole thing is covered in it (literally, no brown spots of cardboard show) this is due thursday, and i'm not going to buy primer for it. just something simple like covering it in wrapping paper, then painting it.