I was taught to --- I guess the word I am looking for -- was to square up the quilt before adding the next border. If the first border was lets say 2" it should be 1 -3/4"after sewing it on. Lay your ruler on it and trim to 1-3/4" all the way
Around.

me too!
 

I'm feeling the same pain! I was working last night to get a Christmas table topper that was all cut out--it's a hexagon so lots of large triangles. I've even made the pattern before! But nothing fits--finally gave up and went to watch Christmas movies with my hubbie instead. Going to try to figure out where I went wrong now--maybe the "brownies" have remeasure and fixed things for me overnight!

For my borders I measure the sides first and cut those border strips the average of the 2 measurements (I don't measure the middle). Apply them and press. Then I measure the top and bottom, average, apply and press. There are several factors that will affect different measurements. If you iron instead of press, your fabric can stretch. If you are using a "plastic" measuring tape, they can stretch. Laying the quilt on any surface can result in an area being stretched. We aren't talking about any major amounts in any of these, but it can cause the quilter to be frustrated and confused. Just do your best.

I agree!on the wavy borders. The quilting police will hunt you down and make you do it over! LOL

Thanks for posting about squaring up a quilt.

To answer your question of how it happened -- quilt gremlins!

They strike all of us at one time or other. Gotta be diligent. Down with quilt gremlins!

I don't know if they'll hunt you down and make you do it over but they'll definitely snicker behind your back.

Easing in is another way to say gathering. If you do enough gathering it's really ruffling. If you want flat borders ruffling is definitely not the way to go.

I see others have given you great advice for measuring and adding your borders so I hope this is not a repeat of helpful tips. When adding borders I pin at the two ends and in the middle. If the quilt is large I will divide it up even more and pin those spots. I also add about a 1/2" of border beyond the ends to allow for squaring-up at the corners (hope that makes sense).

Aside from the measuring, which it sounds like you did right, did you "Starch" or use "Best Press" or somthing similar? I've found it really makes a difference in the accuracy of everything I've done since I've started using Best Press....

Measure twice and cut once. I usually cut my borders a little longer just in case. I would use the longest measurement and cut off the extra as you sew the borders on. Sorry for your problem. No explanation for why this happened.