Bias tape is such a fun sewing notion. You can customize any pattern that calls for it by using contrasting fabric to make the bias tape. My personal favorite is using a ditsy floral bias tape on any plain little girls dress. So pretty! A few of my patterns require bias tape so I thought I would put instructions on how to make 1/2" double fold bias tape on the blog. There are a few different ways to make double fold bias tape but my favorite way to make it is explained below.
The best tools you can use to make bias tape this way are a 6" x 24" quilting ruler that has degree markings on it, a cutting mat, a rotary cutter, a 1" bias tape maker, and a disappearing ink pen.
First, you'll need to figure out how much bias tape you need. If you're using a pattern, you will have a yardage requirements section that you can use to figure this out. If you're making a quilt or something else, you can measure the perimeter of that project to figure out how much you'll need. Once you find out how much you need, you can use this chart to determine what size square you need to cut. Be sure to cut the square so the horizontal and vertical grain lines are exactly perpendicular (90 degrees).
After you've cut the square and pressed it, you'll fold it to form a triangle. Press the fold. Don't worry if the square all the sudden became uneven because we can trim the edges later.
Fold the triangle again so all the raw edges are on one side. Press again. Now you can take a quilting ruler or a precise 45 degree measuring object and trim the bottom raw edges if necessary.
Use your quilting ruler to measure a line 1" from the double folded edge and mark with your pen. Then measure 2" from the first line and continue measuring until you get to the other side of the triangle. Now you'll cut on those lines you marked. I find a rotary cutter is the best way to cut bias tape strips.
After you've cut all your strips, you'll want to trim the ends of the first two strips so they're a 45 degree angle.
Next, you'll place two strips right sides together so that raw edges are touching. You'll want to align the edges so that the seam line is aligned and not the seam allowance. The illustration below is exactly how the two strips should look. Repeat this step with all the strips, then iron the seams open. A bit of spray starch is also helpful for getting really crisp seams.
Next, you use your bias tape maker to finish the long strip of bias you have. Feed the end of the bias tape into the maker and get your iron ready. Pull the bias tape through the maker, ironing as you go. The first run through will fold the two sides in towards the middle as shown in the illustration. If you don't have a bias tape maker, you'll need to do this manually.
Then you'll fold the bias tape in half so the folded edges are aligned. You can run the tape through the maker again, or just fold and iron one section at a time.
And now your bias tape is finished and ready to use!