Here is a one question interview I did for avoidthefuture.com a few months ago.
Q: Why newsprint?
A: The idea behind The Comix Reader is that a group of artists who are somewhat on the same wavelength can come together and combine their work and resources to do something on a scale they wouldn't be able to do alone. If you can find the right printer, newsprint is very cheap. Even using full colour you can print a few thousand copies for the same price you'd pay for a run of a few hundred b/w digitally printed comics. By everyone contributing to the print costs we were able to do a run of 9,000 copies, without needing a "real" publisher. So newsprint offered the thrill of printing lot's of copies and being able to sell them cheap or give them away. It means 9,000 people will see it, and maybe their friends will see it too.
Other than this, I also quite like the idea of having this really inexpensive format. It makes it both collectible and disposable at the same time. It's also a statement against the very well-printed, but very expensive comics that have come out over the last few years. They look amazing as art objects, and will last forever, but the content was often disappointing - or at least not worth the cover price.
Another reason for newsprint is that The Comix Reader is inspired by the format of 60's underground newspapers like Gothic Blimp Works where the very early underground comix appeared. If The Comix Reader can capture a bit of that flavour and energy I'd be very pleased. It's also inspired on some level by early comic newspapers like Ally Sloper's Half Holiday, which was far more mainstream but contained some very coarse rough-and-tumble type humour. This ties in with a final reason for the tabloid format, which is that it may be more acceptable to non comics fans than the traditional stapled comic format or trade paperback. This was another motivation for doing The Comix Reader : to get it out to people who wouldn't normally come across many comics, but who might be interested in them if they actually had a chance to see them... perhaps the kind of people who in the 19th Century would have read Ally Sloper!