Sometimes a quilt can lay flat and opposite sides measure same but it will still hang
crooked...or have a wave. I don't see a point of blocking quilts that will be used
on a bed but if it's for show or to use as wall-hanging it just looks nicer to block.
JMHO.

Edit: I don't do shows but if I were I would block because they would be
hanging on a rod.

I tend to only block those quilts that will be hung either as a wallhanging or in a show--but I don't do big time shows, so even with local fair and guild show I sometimes don't block, especially if it's a bed quilt.

That being said, I will use a cork board to pin the smaller projects onto and with larger quilts, I will lay out a sheet of plastic on the basement carpet, and then pin the quilt to it (and carpet) and set a floor fan to aid with drying (I also run a dehumifer in basement in summer). I try to block with as little water as possible--so will use spray mist for most. Occasionally will put one into filled washing machine and then spin to get excess water out--but make sure you've done a seam around the whole outside first! I also have learned that it is much easier to block BEFORE you bind.
Even when I have worked to keep my quilt square, sometimes with heavier quilting, blocking is necessary to make it hang flat. Remember , besides pulling it to square, you can also "push" excess back into square.
Also, I know some think that you can just lay a square on the corners and check for it being "square"--but I know from time spent on a drafting table that a t-square will look square even when it isn't if there's not a solid, square edge to judge it from. For this reason, with larger quilts I always take measurements and square from that, not just laying a ruler down .

I have quilted since the early 80s and have never needed to block a quilt. Why do you feel the need to do this??

She wants to enter it in a show.

As Peckish said, I'm thinking of entering it in the county fair and I've been told that blocking it will make it hang smoother.
Having been working on it this morning and seeing how much I have left, I doubt it will be done in time, anyhow!

Watson

I have never block my quilts, but I vaguely remember seeing a video and tutorial by Sharon Schambers that she showed how to block one. She has several videos on you tube, you might check her site out. www.sharonschamersnetwork.com

If, bearisgray, everything is flat and even, I wouldn't block it. I do mist mine, measure like crazy, and pin with rustproof pins. After it is day, then, I sew 1/4" from the edge to secure the three layers and then attach the binding.