I had bought these cotton breast pads before the last pregnancy. My flow was so heavy last time that I leaked through them rather quickly. I was afraid that I would do the same thing this time. I figured that putting a pul backing on them would help fix that. So I went to Joann's fabric and bought some pul they were selling. I didn't measure anything. I did exactly what you see. I was pretty sure I had 4 pairs but I could only find 3. I did later find the last pair so I actually have one more set to do. It is important to note that when working with pul fabric, you are supposed to iron it first and then let it cool, not to sew anywhere except the very outside edges, and put in a dryer for 20 min on med heat after wards to reseal the fabric around the holes made by sewing it.
I put them on the fabric to see how much fabric i would need.
I cut squares around them.
I pinned them on the outside to hold them still while I cut off the extra.
I sewed a seam all around the outside edges. I washed and dried them a couple of times. They did not changes shape. I have used these many times and I love the fact that they do not leak straight out of the front anymore. when they are full in the middle they seep to the outside (like a diaper in a wrap). They would eventually leak if worn too long but they worked great for me.