The Joann tartans and the "Target" range of solids (linked by Nik) are two different fabrics. Similar in weight but the Target seems to have a bit more body, just IMHO and from memory of buying both. The Target is a good starting point for your first XKilt, once your feet are wet you will be looking at all sorts of fabric and thinking, hmmmmm, would that work?

Welcome to the addiction!