In the end you can only use it if you are going to use the material smaller than the original for print purposes, otherwise you can get even wilder artefacts, called moirr when the new material will be rasterized again for full color printing. I never want to scan from print anymore, but sometimes you just have to. When it happens I start scanning at double the size (the tip from willf), that is slightly better than upping the resolution after scanning. Getting your hands on the original material that the magazine used is always better!