While the first picture of a typewriter that comes to the mind is an archaic, metallic, clunky one, the story doesn't really give more details to complete the p

While the first picture of a typewriter that comes to the mind is an archaic, metallic, clunky one, the story doesn't really give more details to complete the picture. Perhaps the typewriters are noiseless, electronic ones, with a touch-based input system? Perhaps, they generate characters which can't be traced (with the help of randomized glitches for example). And perhaps they only use paper which is not traceable (if such a thing exists).