Use this bias tape folder give many more options to customise clothing or household items.
You can use regular 12 mm or 1/2" bias tape, this attachment acts as a guide for the bias and the cover stitch machine will sew it directly on to the material being stitches.
You can create effects on garments or make tape handles.
If you were going to make you own bias tape cut 25mm wide fabric strip, then fold approx 6mm fold at each side, leaving 12/13mm between the folds.