No-Wave Borders

It's the first day of school here! Today's topic - How to add borders without any waves.

Have you ever made a quilt that wouldn't lie flat? Or maybe the borders were a little wavy? In order for your quilt to be perfectly square (or perfectly rectangular), the opposite sides of the quilt must be exactly the same size. Chances are when you finished the pieced center, the edges may be off by 1/4 - 1/2". If you just sew your borders on and trim - they will also be off by 1/4 - 1/2". You end up with a quilt that's not square (or rectangular).

Many books and patterns will tell you to measure your quilt with a tape measure and cut your borders to that size. Man, I must be a bad measurer because I tried that for a while and made tons of mistakes!

Here's what I do now - no measuring!

Cut 2 borders a few inches longer than the side of your quilt. Press them wrong sides together.
Lets pretend this block is my quilt. Lay both borders along one edge of the quilt. If your quilt is longer than the table, just put a few pins in and slide it across the table.
Use a ruler and rotary cutter to trim both borders the same size as your quilt. Use the lines on your ruler to make sure you're trimming the corner absolutely square.The bottom strip fits perfectly and is ready to be pinned. Flip the border strip from the top and pin it to the opposite side. It may not fit exactly! Pin all along the edge, easing in either the quilt or the border. It's really easy to ease in a bit along a long border.
Sew; press and repeat the same process on the opposite 2 sides.
Ta da! A perfect square!
I like to use the same technique to cut long horizontal sashing strips to length. I pile up all the sashing strips, lay them along one row of blocks and trim them all at once. Then each row may need to be eased to fit the sashing strip - but in the end I have a nice square quilt!