Persnickety about Paper

Never thought I'd be choosy about paper, but here I am working with copious amounts of it, so I suppose it's a must. When glued, some paper will become wavy. When the glue cures, some paper becomes flat, but others remain wavy. Since I don't really want to sell defective products, I need to have a specific kind of paper - Sinar Spectra. What they sent me was a box (5 reams) of Nordic Star, which turns wavy. Still testing the paper... hope it turns out...