What would make tracing paper clear?
I can tell you how to find something that will make tracing paper transparent, but I don't have an example to hand.

Tracing paper is partially opaque because it is "rough" and contains many small fibres of cellulose that scatter light. These scatter light effectively because of their size and because their refractive index is very different from air. If you can find a liquid which has a similar refractive index, that will make the paper much more transparent than in its natural state. 

I'm sure their are some, but I don't know any right now.