It
is hard to find even a few pages of the paper without color pictures and ads! Check with your local paper's print shop. In the Texas Master Gardeners class several years ago, when discussing using newspapers as mulch and weed barrier for vegetable gardens, we were told that
most of the inks now used are vegetable-based and not petroleum-based, and thus safe; but
there are still exceptions. Petroleum-based inks will release harmful chemicals into the soil when wet. Also,
never use the slick paper that magazines and lots of ads are printed on. Now this information comes from the Texas A&M Agricultural Extension, so I feel that it's accurate. If there's another reason, I'm sure someone will come along and explain it.