I have had problems in the past with my boarder having ruffles. Sometimes only a little or on one side. Sometimes all around. Sometimes I can "pin" them out. But other times not.

What causes this to happen?

Usually the border is slightly larger than the quilt. Measure the quilt across the middle and both ends. Take the average and cut the border that length. Then carefully pin to the border to the quilt.

are you cutting your border strips across the width of the fabric? that's the "stretchy" direction. it uses less fabric, but takes a more careful approach if you don't want the quilt to wave at you.

first (and others may disagree) i highly recommend you starch the bejeezers out of your border fabric before you cut. the stiffer the better.

second, get out those straight pins. pin at least every inch. i'm a great believer in overkill, so i pin every half inch.

third, if you have one, use a walking foot to stich the border down. it all but eliminates the "creep" of the underside while you're sewing.

i have better results when i stitch mine with the border underneath. others report that things go better for them if they do it the other way 'round. try it both ways so you can decide which works best for you.

I agree with Patrice. Pinning a lot seems to help me. If I don't that quilt will be waving at me. I don't starch but I can see why it would help too.

Something I saw on TV yesterday was this woman that was blocking a quilt. She used water to do it. What if you spray your border with water. It needs to be really wet and then try to ease it up in the areas that are needed and let it dry flat until dry? It might make the material go back to its original shape.

I like the walking foot tip. I am going to try that.

the fabric stretches. all of the above are great tips! I have taken to using my walking foot for ALL border and binding sewing. Amma enlightened me on "glue basting" for binding. I wonder.... how well that would work for borders. hmmm??? I will have to try it.

For the first borders I also measure in three places - I lay the top out flat and then measure both sides about six inches from the edge and down the center and take an average of the three measurements.

Then I cut a strip several inches longer than that (I'm a cautious type) on the lengthwise grain of fabric (If I have enough and/or the design "works")

I divide the border strip as illustrated. I also divide the quilt edge the same way.
Then I match up the points.

Then if one side needs a little bit of easing, it's distributed fairly evenly.

if it's too wavy it's probably too long, I would take it off, remeasure then use the above suggestions, it's a pain I know but it feels sooo good when you get it right and it looks better.

Thank you for all the great tips. Now I understand why it does this. I have also found if I am very careful about squaring up the corners I don't get ruffles. I love this place. I get the best information and idea.