You don't need to use a specific "newsprint" paper, any lightweight paper with some slight texture (so it's not slippery) will do the job. e.g. In China we have a type called "Dowling Paper", it's yellowish, and it was used to print books and school test papers. Those are cheap as well. Or you may just use some thinner office paper, like 70gsm ones, I don't think they are sold in big sheets but up to A3 should be easy to find. Otherwise, you could use those rolled paper for large format printing, we sometimes refer them as technical drawing paper, not thick as well, they are often available as a lot of advertisement shops will have those big machines for printing posters and stuff.

Hey Ruben, newsprint is pretty popular so its strange that they don't sell it. A bit more expensive alternative is bond or bleedproof. The main thing is that its smooth. Really smooth.