While you can find lots of tutorials on creating your own bias binding, I’ll go ahead and give a little tutorial of how I created mine for use as trim detail on the armholes and neckline of the polka-dotted dress.
First, I cut a piece of fabric 16″x16″. (You may think this won’t create much bias trim but you would be wrong! Ha ha. It created at least a couple of yards for me. I used it for the armhole trims and neckline trims of my dress, and I still have lots left over.)
The top and btm edges should be noted in some way –I used blue pins on the top and bottom– and then the two sides should be noted differently — I used yellow pins. Cut the square piece of fabric diagonally in half. (Step 1 below)
Place right-sides together (which is easy if you have an obvious right and wrong side like I did with the polka-dot fabric), then align matching pin colors edges, but let the point of the triangle extend by 1/4″ on the left and right sides. (Step 2 above)
Then stitch the two pieces together along that overlapping edge. The 1/4″ overlap guides you –it’s the seam allowance width (1/4″). (Step 3 above)
TIP: the reason for the extended wedges is so that after the pieces are sewn together and pressed flat, the edges will align perfectly. (Step 4 above)
Next, draw 2″-wide lines on the flat WS of the piece, starting from the top and continue drawing parallel lines across the big piece until you can’t fit another 2″ row. At that point trim off any excess that can’t be part of a new 2″-wide row.
TIP: use vanishing ink that disappears in the wash or use chalk, like I did. The important part is to not use anything that will bleed through to the RS.
Bring the two long, angled sides together (RS together), matching up the end points of the lines you just drew, but then shift one side up by exactly ONE row to begin. Then shift the two aligned edges 1/4″.
(I can’t remember if you shift up or down, but the reason for the shift is to ensure your drawn lines match up after you stitch a 1/4″ seam. You can pinch the edges together with your fingers and see if your drawn lines will match up, if so, you’ve shifted in the correct direction. If not, re-align your edges by your drawn lines and shift in the opposite direction 1/4″.)
NOTE: I ended up making more bias trim for the hem, so I took some pics of the alignment of the angled ends with the drawn lines in disappearing ink (below left) and after it was stitched together (below right). This was only a 12″-square piece of fabric to start, so it made less bias trim, about 1 yard. )
Here is my original stitched-together piece that is shifted as described. Notice my chalked lines are perfectly aligned across the seam allowance. (Those drawn lines will end up being your cutting lines to follow.)
Then you can stitch these two angled edges together with a 1/4″ seam allowance. (See above picture,) Your drawn lines should MATCH UP once the edges are stitched together. This is critical to the cutting part that comes next. Press that finished seam open.
Now it’s time to CUT apart this big piece into one, long, continuous strip of bias fabric. Start cutting at the 2″ row that is sticking out by itself at the top of your piece. (See my sketch below). Then continue cutting along your drawn line, which wraps round and round the piece.
Once you start to cut along the drawn lines, the bias strip of fabric will get longer until you cut into the last part of what used to be a big rectangle of fabric. Now you have a whole bunch (yards!) of bias binding ready to start using.
I wrapped mine around one of my pressing rolls so it didn’t get wrinkled. I’ve seen some people use a toilet paper roll– whatever you have handy is fine.