I have a bunch of newspaper that I am shredding for mulch, and was wondering if those shiny newspapers are okay for mulch ? My son thinks so as he worked for a printing company and says it is only wax that makes them shiny, and they use all soy inks. I just don't know. moderator's note: added a more descriptive title to topic
Some will say no, never....some will say if the wax is plant based and not petroleum based then it will be okay. You might call the newspaper office to see if you can get an answer about the wax used.
Generally speaking, "slicks" don't do well as mulch or compost, but regular newspaper does. I don't use slicks personally. Your son is right about the soy inks, but I'm not sure the colored inks in slicks are soy-based. Perhaps someone here will know. When I put newspaper down as mulch, I wet it thoroughly. You would not believe how much information can be dispersed over a large area when the wind rises and the newspaper is dry!
I've gotten wildly different takes on four color (slick) newsprint, from people active in press work. My take is some use soy inks, and some still don't. Matte newsprint is just about all with soy inks.