Put simply, blocking is a way to flatten out and ensure a quilt is square and true at all major visual elements such as blocks and borders. It will remove the built in stresses introduced into the fabric fibres during construction and quilting and will ensure the quilt hangs flat without ripples, puckers and waves. The drape of the quilt is greatly improved,particularly where heavy or dense quilting has been used and the textural quality of the quilting becomes much more apparent.
When we quilt, especially machine quilt, we add stresses, tension and possibly even some minor distortion into the fabric fibres and a good " blocking" will help to relax the fabric fibres and reduce/remove any distortions and size variation throughout the quilt blocks. Some quilt tops are not square before quilting. They might have 'wiggly' borders and/or individual blocks that are out of true. If we are careful when we quilt we can introduce a " little attitude adjustment" to help correct these problem areas and a good blocking prior to binding will underpin and support these adjustments.
On a practical note, techniques such as Trapunto often require a full wetting to remove water soluble thread and once wet the quilt will need to be laid out flat and reshaped before drying. Heavy quilting used to create faux trapunto effects also respond well to blocking as the wetted quilt will shrink up to accentuate the trapuntoed areas. If left unblocked the quilt may look distorted and hang poorly. However, once dried a blocked quilt should hang flat, square and true and retain this shape until the next time it becomes wet.
The Blocking Process
Step 1 : Half fill a bath tub with luke warm water. Not cold and not hot! Add at least 5 or 6 dye-magnet sheets - these are the sort that attract surplus dye floating in the water.
Even if you have a large capacity washing machine I would still advise using a bath tub for this step simply because you can see what is happening to your quilt while it is in the water and you can gently agitate it to remove soluble thread, quilting marks and any localised soiling.
I use Colour Catchers - available on the laundry aisle at Tescos and other supermarkets. I think they cost around £3 or so for a box of 12 . I also add a small amount of liquid soap such as orvus paste or similiar.
Step 2 : Add the quilt - keeping it as loose and open as possible. Leave it to soak for a few moments then agitate the water around the quilt and use the palms of your hands to gently agitate the quilt itself. Do not wring or maltreat the quilt at this point otherwise you stand the chance of breaking quilting threads!
Look at the excess dye in the water!
The dye magnet sheets will prevent this going back onto the quilt.
Remove the dye magnet sheets
Step 3 : Drain the water from the bath tub and refill with luke warm water.
Gently rinse the quilt and drain the water again. DO NOT wring the quilt to remove the excess water.
Let the rinsing water drain away. Gently pump the quilt with the palms of your hands to help with the draining process but DO NOT WRING! It will take 5 -10 minutes for enough water to drain from the quilt for the next step.
Step 4 : Place a large clean white towel or sheet in the bottom of the bath tub. Roll the quilt onto the sheet or towel. ONLY use the sheet or towel to support, lift and move the quilt.
Step 5 : Move the quilt to your laundry room and gently place it into the drum of the washing machine. Note: European front loading machines are big enough for a queen/king size quilt once they are wet!
Step 6 : Spin the quilt to remove as much water as possible.
Step 7 : Remove the quilt from the washer and place it in a bucket for support while you move to an area large enough to spread the quilt out flat.
Step 8 : Lay the quilt out on the floor.
I have a laminate floor in my studio that I am happy to put a damp quilt directly onto. (If you are not happy to do this securely tape a piece of plastic sheeting to the floor area first.)
Lay the quilt on the floor and gently tease the quilt into shape. I start at the centre of the quilt and use my hands to pat and tease the quilt outwards making sure it it flat against the floor as I do it.
Step 9 : Check for square.
You will need to check for square several times as you adjust and readjust your quilt. I pick a major design element such as an inner border first to check the squareness as follows:
Using a metal tape measure measure the diagonal right to left through the quilt. Make a note of the measurement.
Now check the left to right diagonal and make a note of the diagonal. Is it the same as the right to left? If it isn't then your quilt is NOT square. To make it square gently manipulate your quilt until BOTH diagonals are the same.
If you find your are having to stretch your quilt out to make it square use T-Pins if your base floor is carpeted to secure in place or use small lengths of grossgrain ribbon pinned to the edge of the quilt on laminate floors. These ribbons can be pulled out to gently adjust the quilt and can be secured to the floor with masking tape. Usually I allow a good 5"to 6" extra on the quilt top to account for any shrinkage during quilting and blocking so I prefer to ease in out of squareness as opposed to stretching it out.
Once you are happy the quilt is as square as possible, check for waviness! I use a 90 degree laser level to check this out. See the red line on the blue border? One you have positioned the laser you can tease the border in or out to meet the laser line.
A metre metal rule is also helpful in this straightening process. Be patient and take your time to get things as good as they can be. I think I spent the better part of an hour or more getting this quilt laid out the best I could. You can see how wavy this border was before I blocked it.
Once you have laid your quilt out and it is is as flat, square and unwavy as possible - LEAVE IT ALONE! Let it dry for at least 24 hours or longer. A fan will help speed up the drying process but do not move the quilt until you are satisfied it it thoroughly dry. The quilt is now ready to be trimmed, stabilised and finished with a nice binding. See here for detailson how to stabilise and finish the quilt.
For details on how to launder a quilt look at the free download on my website here
