I'm sure there are probably better ways . . . but here's one way. Take some brown craft paper or freezer paper (anything that's at least 36" wide). You'll also need a long ruler (yardstick, at least). Tear off a good-sized length of the paper (at least a yard) and fold it in half (this will represent a quarter of your cloth). On one fold point, mark a large dot. Measure from the folded-point end of that dot, to the opposite side, and mark 30". This will represent half the width (radius) of your cloth. You'll need a seam allowance, so mark another point, shorter than that (I would allow 1/2" seam, unless it'll be backed). Now you'll make a third mark, longer than your cloth measurement, to represent the outside of your border, plus hem allowance. Okay, so you've now got a starting dot on one side, and three marks away from that dot, along an edge. Take the ruler and keeping one end of the ruler at the dot/point, move the other out just a bit. It should move like the minute hand, on a clock. Mark the innermost and outermost measurements. Keep sweeping your ruler out, bit by bit, marking the two measurements, until you reach the other side. You should end up with a inner and outer quarter circle. Connect the dots and this will be a pattern for 1/4 of your border. Remember to add seam allowances at the ends, if you need to piece two or four pieces together! If you cut along the lines and unfold, you'll have a pattern for half of your cloth border . . . but be VERY careful, to keep the two layers of paper perfectly together, when cutting! You can staple (or use a temp. glue stick) them together, to keep them from sliding.
Am hoping this makes sense, translated into words!
