While it may be convenient to buy the paper...I have never done so. Being on the green side I use paper from magazines only. Once photography is important to a mag u get good (clay content) paper to reuse.
Thus the majority of Women's mags, like Style, Seventeen, Oprah, Better Homes, Women's Health, Elle, then u have the other quality mags like Nat Geo, Smithsonian, Astronomy. You get an enormous amount of pages in magazines like Style, one mag. might last you a year, unless u want text only pages to use.
Don't use the paper in the giveaway catalogs like Parts Express, Harbor Freight, Jameco and so on....you get a 50% failure rate. Avoid paper that has dark images. Light coloured pics and text work the best for me.