1. I always pre-wash my fabrics so the colors won't run when exposed to water. What is the point of blocking if your colors bleed all over the place?
2. Do not bind your quilt yet. Measure the unbound quilt (see the diagram below). Measure across at the top, center and bottom (red). Measure vertically the left side, center and right side (purple). Be sure to include the amount you need for binding. For a square quilt add up the measurements and average (divide by 6 in this case). If your quilt is rectangular you will average the three measurements of the length (divide the total by 3) and the same with the three measurements of the width. Average the two diagonals (blue) in the same manner (divide by 2). Hopefully the measurements will be perfect, or at least very close. A difference of 1/4 inch will work out, 1/2 inch makes me really nervous, 1 inch would destroy my day.
3. Use your average measurements to trim your quilt, adding at least the width of your binding. Be sure to cut your corners square. A 12" square ruler is a great tool for squaring the corners.
TIP: If you allow more than the amount of the binding, plan another trim session after the blocking is complete.
4. When the quilt is finished, but not yet bound soak it in the bathtub for a couple of hours then gently squeeze out as much water as possible; do not twist. You can also use the washing machine but do not let it agitate. Leave the lid up so it will soak without getting beat up. Then spin the water out gently. The washing machine is certainly easier, but I can't use mine in the winter so I have used both methods with good results.
5. Now comes the fun. You need a flat surface that you can poke pins into and that will allow you to stretch the soggy quilt as needed. You can place a clean sheet or blanket on the floor and pin the quilt to your carpet. I prefer a big piece of styrofoam. I bought two 4x8 ft. pieces with silver paper on the outside, and taped them together with packing tape. This monster fits nicely on my bed or a large table, and I don't have to crawl around on the floor picking up pins in my knees. It is light weight to move around and stores easily on its side - even with a quilt pinned to it, as occurs when I want to go to bed. Next I use painter's 1" masking tape to mark where the edges of my quilt need to be pinned, measuring carefully as I stick it down. Mark the center of all sides with a permanent marking pen on the tape. Using the tape eliminates constant measuring and repinning, which can get exhausting.
TIP: Caution!! Cats and dogs love the carpet method. Your lovely quilt is the perfect place to curl up for a nap.
6. Now you are ready to pin. The directions I have read advise using T-pins, but the ones I have are too big and too difficult to stick through the wet fabric. I bought some long, sewing pins and they work much better. Place the pins in the edge of the quilt fabric where pinholes will be covered by binding. Pin the four corners first. Then pin the centers of all four sides, pulling the quilt to the edge of your carefully measured masking tape. Place pins about 1 inch apart all the way around your quilt, easing if necessary.
TIP: Don't be afraid to ask for help. Sometimes you need an extra set of strong fingers to encourage the fabric to knuckle under to the averaged measurements and meet up with the masking tape.
TIP: What if you have the edges all pinned, but there are pouffies in the middle where there seems to be too much quilt? Pat the excess down gently, but don't squash your beautiful quilting. Go back frequently and pat your damp quilt lovingly until it dries nice and flat.
There is a great deal of satisfaction in seeing a completed quilt pinned into submission all clean, flat and lovely. Quilting imperfections seem to have disappeared into the batting and you almost wonder if you really made it yourself. When it is dry, double check the measurements, and you are ready to bind it. It will maintain its shape as long as it is kept dry.