Prism99, your explanation has helped me understand this problem! I've known to measure in the middle, but did not know why!! Thanks for that... And Dray965, good luck!! We're cheering you on!!

Prism99, you presented a great explanation/tutorial for us. Thanks.

sewnclog......
I have made garments for many years. If I ever wanted to work a bit of fullness in (especially helpful on set-in sleeves), I always put the larger fabric on the bottom so that the feed dogs would help me work in the extra. This works great with clothing, but with a quilt, it tends to make the bottom piece pull a bit more through the feed dogs and the extra could make the border wavy if it was on the bottom.

I don't have a lot of problems with wavy borders. I always measure my border length, but don't cut. I put a pin in at the end point. Then I pin at the 1/4 point, the half way and the 3/4 point and each end. When I sew I try to keep both the top and the bottom taut while sewing. The pinning really helps keep me or the sewing machine from pulling either side in more than the other. I cut after I finish the sewing and find out if it looks good.

My quilting teacher taught us to measure (for our border) in 3 places across the quilt: the middle and each end. And then cut your border to the average.

Ex: Your measurements come to 34 5/8, 34 1/4,and 34 3/8 inches . Add those up. Divide by 3. That's your average. (To anyone who has forgotten how to convert fractions to decimals, the "line" in the fraction means "divided by". I don't mean to "talk down" to anyone, but since math is NOT my strong suit, I sometimes need simple reminders from 4th grade. LOL)

In this case, total is 103. 103/3 =34.33. I round to the nearest 1/2 inch if the answer is "weird" like that (great math word, huh?). So, 34.5 is the length of the border you'd cut in my example.

It's easy to forget that the layers of the quilt don't all get "chomped on" by the feed dogs at the same rate. Hence, the waviness. Believe me, everyone's done it.

If you can't ease in the wave, just make a couple small darts. Place them so they look like it was a pieced border. If the seam bothers you, add some sort of applique that adds to the block or design of the top. Or even a nice embroidery stitch to tie it in. But a small dart in white will probably not be visible to anyone but you.

It will be sticky if you have already done the spray basting, but it can be done. If you have enough fabric to make a new border I would probably do that instead.....

You can stick tissue paper to the sticky and stitch right through it, than tear it away. Ask me how I leaned this.....

There is also a different stretch to fabrics cut lengthwise or crosswise .

After reading through all the suggestions, I think I know what caused it.

I always measure through the middle, lengthwise and widthwise, before cutting my border. Did that, so this isn't the reason.

In the list of suggestions that was given, I'd done everything correctly, except for one. I did cut the border WOF. I've done this many times before with no problem, but I suspect those fabrics weren't as stretchable as this one. I now think that the WOF was not a good thing for this material.

I'm going to try the gathering first, if not pleased, I'm trying the darts. If still not good, I'll take it off again and redo. My lazy-man's method may make me do more work in the end. I probably should do the frog stitch (rippit, rippit) and start over. LOL

Thank you for all your suggestions. It's certainly been a learning experience and I've learned again from this failure through all your 'reasons why' this happened.

Many thanks and if successful, I'll post a pic to let you see solution.

Dray