Bias binding is great for bunting banners, finishing hems/edges on clothing, and of course, for binding quilts. Continuous bias is fast and easy to make and doesn't waste any fabric. Here's what you need to know to make your own binding.
You're going to need a rotary cutter, scissors, a pencil, a clear ruler (or two), a bias maker if you're planning to make double fold bias (I'm using a Clover 25mm bias maker), an iron, and a sewing machine.
There are formulas available on the internet on how to calculate the size square you need to cut based on the total yardage of bias you need, but I never had much luck with them. I just estimate and hope for the best...
Start by cutting a square of fabric (mine is 22" square). Make sure the right side of the fabric is facing up. Next, cut the on the diagonal (the bias).
Flip the right triangle over and place it on top of the left triangle so that right sides are facing.
Offset the two triangles 1/4" so that the pointy ends stick out (adjusted for seam allowance).
Pin the edge and sew a 1/4" seam.
Press seam open.
Lay the piece out so that the wrong side is facing up like this:
Double check that the bias is running up and down by pulling on the top and bottom edges. It should stretch easily.
Next, draw a line 1/4" away from the top and bottom edges using your fabric pencil and clear ruler. This is the seam allowance for making the tube. By marking it now, matching up the cutting lines later will be much easier.
I need my bias strips to be 1 7/8" wide to make my 25mm double fold bias. I will now draw as many lines as possible 1 7/8" apart starting at the top seam allowance line and stopping at the bottom seam allowance. If you're making quilt bias, you'll want to make your strips 2 1/2" wide or more or less, depending upon your preference. I personally prefer 2 1/4" wide. If you're making bias binding for garments, refer to your pattern or use the width guidelines that accompanied your bias maker.
Once you've drawn all the lines you can, trim off any excess fabric that's not wide enough to make the bias strip using your ruler and rotary cutter. I just have a small amount of excess on mine.
Flip the piece over so that the right side is facing up, then fold over the top and bottom edges to form a tube. Instead of lining up the cut lines perfectly, offset by one like this:
Now you will pin the seam to make the tube. Stick a pin the second "intersection" (the point were the vertical and horizontal lines meet) from the left.
Then fold the fabric over to make sure that your pin goes through the intersection on the other side.
Continue this method until every intersection has been matched up and pinned. If your intersections don't line up (like mine didn't - aaargh!), you'll need to go back and remeasure and redraw your cut lines.
Now sew a seam along the line you drew across the top edge, pulling out the pins as you go.
Press the seam open. I slide my tube onto a sleeve ironing board, which works like a charm.
Slip your left arm through the tube (assuming you're right handed). Start cutting along the cut lines. Get comfortable as this may take awhile depending on how much fabric you're working with.
My 22" square just turned into 20 feet of 1 7/8" wide bias!
Clip off the little triangle tag (seam allowance) on each end.
If you're making quilt binding, you simply fold the bias strip in half, wrong sides facing, and press. If you're making double fold bias, keep reading.
Head over to your ironing board with your long strip, a pin, and your bias maker. With the wrong side facing up, thread the angled edge into the bias maker. Use a pin to push it through.
Once you've fed some fabric through, grab it with your dominate hand and pull out about 4-6" and then start pressing with your iron. I slowly pull on the handle of the bias maker with my left and keep pressing with my right.
This process gets a little thorny when you get to the seams. Put your iron down and use a pin or your fingers to get the seams through the maker. Make sure the seams stay open, then press.
Continue until the entire length of bias is pressed.
To finish, fold the bias in half and press again.
Congratulations, you're done!
P.S. My very wise sister-in-law would like to suggest that the easiest way to making bias binding is to grab your car keys and your purse and drive to the nearest fabric/craft store and buy some ;)