Paragraph 143. There are two kinds of bias strips, true bias and untrue bias. A true bias is cut at an exact angle of 45 degrees by folding the warp threads of the material over on the woof threads and cutting on the diagonal formed. An untrue bias may be cut at any angle smaller or greater than the perfect diagonal. Bias strips are sometimes cut by folding the material in such a way as to cut through several thicknesses at a time; this method is rapid, but not so accurate as the method just given.
Bias strips are used to face curves, to bind seams, to finish the raw edges of embroidery ruffles, in place of embroidery insertion, to finish embroidery beading on the edges of corset covers, as piping for dress trimming and in a variety of other ways.
Paragraph 144. Be sure the ends to be joined are cut on the bias ; lay these ends together so the threads will run parallel (the strip will thus form a V shape), allowing the points to extend over each edge as shown in No. 1, Figure 50. Stitch together being careful to do it just as shown in the illustration. Straighten the strip, and press the seam open as shown in No. 2; trim off the points even with the edges thus forming a straight continuous strip as shown in No. 3, Figure 50.