Probably a stupid question but what does it mean to block a quilt? I've heard the term several times but I'm not sure how it's done. I'm assuming you do it to make sure your quilt is square...

Correct!! :thumbup:

Yes, especially after washing/drying quilts can become out of square.
Dampen the quilt, lay it out and pin it down making sure it is square up. Carpets work great for this. :D:D:D

If you washed your components before cutting and all the pieces/blocks were "square" when you assembled them -

Blocking is rarely necessary.

That's not necessarily true. Distortion can be quilted into the quilt, something I'm guilty of.

If I'm entering a contest, blocking will help my quilt hang straight. If the quilt is going on my bed, I wouldn't bother.

Janet

Dampen it, pin it square, walk away and let it dry completely.
Dampening it lets the fabric relax enough for you to tug it to the wanted position.

visit Ricky Timms web site- he has a pretty good tutorial on blocking/squaring a quilt.
quilting can distort the edges easily- but it's not always necessary to do it- if you want it to hang straight- then block & square- if it's going to drape on a bed- you wouldn't really need to- unless it is really out of whack

Sometimes sewing several rows or blocks together in the same direction can also distort a quilt. I had to block one recently and I used a can of spray starch to saturate it, then pinned it to the mattress of my king sized bed. The starch really helped it to keep it's new square form once it was dry and the pins were removed. You need a LOT of pins to do this, sometimes one pin for every half to quarter inch along the edges.

I always block my wall quilts and any show quilts. It makes a big difference in the way they look when hanging.

One thing to remember about blocked quilts, however, the blocking only lasts as long as the quilt stays dry. If you wash it it'll go back the way it was.

Here's more info from Quilt University. http://www.quiltuniversity.com/blocking.htm