One trim you'll use a lot of in home dec sewing is bias tape. But how did it get that name? When I hear the word "bias," I tend to think of Olympic figure skating judges. If you go look it up in dictionary, you'll see that the first definition is "an oblique or diagonal line." (Figure skating is never mentioned.) It makes sense then that bias tape is a strip of fabric that's been cut at a 45˚ angle to the weave or grain. This gives it just a little stretchiness, making it possible for bias tape to go around corners without bunching up. It's easy to make and easy to attach--as you'll soon see.

Bias tape is often used to make cording. But it's a versatile trim just by itself. You use it to cover the raw edge of fabric to give a finished, professional look. It's traditionally been used on quilts and blankets but also makes a nice accent on pillows, curtains and table linens. You can buy ready-made bias tape, pre-folded and ready to go. But there are a number of reasons to make your own, the chief one being you can use whatever fabric you want.

Before you do anything else – prewash!

You notice we say this a lot on Sew4Home. But if you've ever seen what can happen when you launder an item made with fabric and/or trims that haven't been pre-washed, you know it's not a pretty sight. Shrinkage, bunching, wrinkling ... don't go there. The only time you don't have to pre-wash is if you know for sure your item will never be laundered (like a lampshade). Otherwise wash and dry your fabric and trims according to the fabric directions.

How much fabric do I need?

If you're a modern-day Pythagoras, you can figure out down to the inch, how much bias tape a yard of fabric will yield. Otherwise, you can just get a rough idea and then cut more if you need it.

First, measure for the length of bias tape you'll need. For instance, if you're going to use it on an 18" x 18" throw pillow, add up the sides (18" x 4) and you'll see you need at least 72" of bias tape. Always make a bit more to account for the seams and the "tail" you need at the end to fold under for finishing. And because too much is always better than not enough.

Next, decide how wide you'll need to cut your strips. To bind an exposed edge (the most common bias tape use in home dec), you'll want to use double-fold bias tape. If you want your sewn-on strip of tape to be ½" wide, you'll need to start with a strip of fabric that's 2" wide.

For our instructions we'll use 1 yard (45" wide) of fabric. This will give us several yards of ½" double-fold tape. You'll attach your strips end-to-end to get a continuous length of tape.

Cutting your bias strips

1. On your cutting surface, lay your fabric out flat, right side up, with the selvage running along one side.
   
2. The selvage is the woven edge of your fabric where is was originally attached to the loom. The fabric's pattern does not continue onto the selvage, but there is likely to be some information printed there that identifies the manufacturer or designer.
3. Fold the fabric back diagonally so a straight edge is parallel to the selvage.
4. Press the fold and use this crease as a guide to mark your parallel lines.
5. Use a straight edge to make continuous parallel lines at the width you figured above.
   
6. Cut along these lines with good, sharp scissors or a rotary cutter and straight edge.

Joining the strips

1. Square off one end of each strip you intend to join.
   
2. Take two of your strips and place them right sides together at right angles to each other.
   
3. Draw a diagonal line across this right angle corner.
4. Stitch along this drawn line.
5. Trim the seam allowance back to approximately ¼".  
   
6. Lay flat, press the seam open and trim off the overlapping edges.
   
7. Repeat until you have one long fabric strip.
8. Press the seams flat open.
   

Folding your bias strip

1. Fold your strip in half lengthwise, wrong sides together and press.
   
2. Open up your strip wrong side towards you.
   
3. Fold each side towards the center crease and press.
   NOTE: Here's a favorite trick picked up from the bias tape you buy pre-made in the packages: fold one side nearly all the way to the center fold mark – so it is almost touching the fold; fold the other side just a little over half way to the fold line. So you end up with one fold that is slightly narrower that the other, BECAUSE that way when you stitch it on, you stitch the narrow side down first and then when you flip it over to do the final topstitching (don't worry .... I cover this below), you will be assured of catching the wider fold in your seam line.
   
4. Fold again along your first crease, right sides together, so your two folded edges are together. Press. You've just made your own double-fold bias tape. Call all your friends and brag. Or, if you're the modest type, simply move on the attaching it.
   

Attaching bias tape to a straight edge

1. Lay out the fabric to which you want to attach the bias tape,  right side up . Unfold the NARROW edge of the bias tape and position it right side down along the edge of the fabric, lining up the raw edges. I like to position my bias tape just a tiny bit below the raw edge of my fabric. I think it makes a cleaner edge. 
   
2. Stitch the bias tape to the edge of the fabric, following the fold. You are stitching right in the fold line, which makes it real easy to follow and keep your stitching straight.
   
3. Fold in your edges to make a nice, clean edge so you won't have to deal with them later. About ½" should do it.
   
4. Fold the bias tape over the edge of the fabric, encasing the raw edge. The wider folded edge is now on the back side of your fabric.
   
5. Press. This is optional, but I think it makes it easier to do the final topstitching when the entire edge is nicely pressed.
6. Flip over to the right side of your fabric. Edgestitch the bias tape in place along the right side. That means you stitch a straight seam close to the folded edge of your bias tape. You can use a decorative stitch with contrasting thread for an added effect. When you flip over to the back, you'll see that you've perfectly caught the entire length of that ever-so-slightly wider fold on the back. Yea!
   

Attaching bias tape to a curved edge

Your steps for working with a curved edge are essentially the same as the straight edge. It just takes a little extra patience and practice. Here are a few things to remember:

1. Do not stretch the binding as you sew or pin.
2. Start your stitching on the gentlest part of your curve; the place where it is the closest to being straight.
3. Stitch slowly, easing the fabric into the binding as you go. To keep “on track", stop periodically, with your needle in the down position, and pivot your fabric slightly.

Turning the corner – or how to make a mitered corner with your bias tape

Note: you will not be able to make a clean mitered corner unless your raw edge corners are sharp and true.

1. Always start in the middle of one side and work from the right side of your fabric. Unfold and pin bias tape to the right side of your fabric as described in the steps above.
2. Stitch the bias tape to the edge of the fabric, following the fold – also as described above.
3. Stop stitching ¼" from the corner. Back-tack to secure your seam.

   
4. Remove your project from the machine and clip your threads, but do not cut the bias tape.
5. Fold the bias tape straight up to create a 45˚ angle at the corner. 

   
6. Then, fold bias tape back down to make a 90˚ angle at the corner. Make sure your edges are lined up. Pin in place from this angled corner to the next corner.
7. Stitch in the fold from the corner point to the next corner. To find the exact corner starting point you can measure from the side edge of the tape to your fold line. Then, measure this same amount from the top edge. Start in the fold at this point. 

   
8. Repeat these same steps at all other corners.
9. When you’re done and have made it back around to where you started, remove your project from your machine and clip all threads.
10. Fold your bias tape up and flip your project over. You’ll see that a mitered corner forms automatically on the front side, but you’ll need to futz with things a bit on the back. I’m not sure if “futz" is an official sewing term, but it describes what you have to do to work with your corners, which will kind of curve out due to the pleat you made on the other side. 

    
11. Fold down the corner so it creates a diagonal line across the edge of your fabric’s corner.

    
12. Fold in the left side to create a 45˚ point.

    
13. Fold in the right side to create a matching 45˚ point.

    
14. Press well. Pin everything in place. To be extra safe, you could hand baste everything in place.
15. Depending on the width of your binding, you may want to slip stitch the back of your mitered corners to close any gap left after edgestitching.

Finishing

1. Remember when you measured your project for bias tape, and you added about an 1" or so to make sure you had enough for finishing the end. Remember that? You did that, right?
2. Now that you’ve made all your pretty mitered corners, and have them pinned or basted into place, you need to deal with the end of your bias tape. In the middle of the edge where your two ends come together, one edge should be stitched down and the other end should have that loose “tail" you accounted for at the beginning.
3. Fold under the end of the loose fabric to create a clean edge and wrap around the ends. Overlap about 1/2" and pin in place, matching your bottom edges.

   
4. Flip your project back over to the front and edge stitch all around to secure. If you’re worried about catching the back of your bias tape, you can edgestitch from the back. Just make sure that your bobbin thread is the correct color and that the bobbin tension will create a smooth, even stitch ... because if you’re stitching from the back, the bobbin thread stitching is what will show on the front.

   

Once you've done it, you won't believe how easy it is. Sometimes it's good to just practice on a scrap of fabric until you get the steps down and are happy with how your finished edgestitching looks. Like Mom always said, "Practice makes perfect!" Thanks, Mom.