square when folded in quarters. The red and white stripes around the edges is the hem allowance. Finish off as you please. And have a Merry Christmas!
While a fat quarter on any fabric gives you enough napkins for a gathering of four, if you're having a big party a full yard on 42- inch fabric will get you 16 napkins. The widest fabric - 56 inches - will get you 4 napkins on a fat quarter but 20 on a full yard. (And the wider fabric on both fat q and yardage will give you a bit of useless partial napkins, as well. Hmmmm ... Wait! You could use the partial napkins to make Santa-face ornaments for your tree! Yes!)