Wednesday, September 19, 2012
Cutting Fabric - where I go on and on about my least favourite part of quilting
As part of the Mod Pop QAL, I will set out my approach to cutting fabric. Although this is my least favourite part of quilting, it is a step which makes a significant difference in the ease of construction and overall final appearance of your quilt, just as it is a critical part of garment making.
While I appreciate that most of you cut fabric all the time, there might be some who have some questions. So this post is to share my approach, which is not necessarily the best one but it works for me. I used a fat quarter and this approach also works for a piece of fabric cut across the full width of fabric.
It is important to remember that fabric is woven in a grid. The threads that go from selvage to selvage are called the weft and the other threads are called the warp. When fabric is woven, the warp threads are set up on the loom or machine and the weft is woven across them, so generally speaking warp threads are stronger or better aligned than the weft. If you hold your fabric and try to pull it along the warp threads, there will be little or no "give", there is a slight more "give" if you pull along the weft threads, but if you hold it at a 45 degree angle to the warp and weft and pull, it will stretch a lot. This is called the bias of the fabric.
Therefore, when you cut fabric in straight lines - strips, squares, rectangles - it is best to cut along the warp or weft fibres which will give you a strong edge that does not stretch. It will also unravel less. When you cut a curve, you are cutting across the bias of the fabric and it becomes very easy to stretch the fabric as you handle it, or later as you are sewing it, thus distorting your pieces.
So, the first step in cutting your fabric is to try to get a nice line along the weft or warp fibres to work from. To do this, first press your fabric. I pre-wash it too, but many quilters do not prewash and I leave this debate to others, stick with your own preference.
Check that the edge of the fabric opposite the selvage edge, if it is not the selvage, is cut along the warp - if it is you should be able to pull the next warp thread off easily all along its length. If it is not cut this way, trim it until it is. Then fold the fabric so that the selvage edge is meeting the opposite cut or if your piece of fabric is larger, so that the selvage meets the other selvage.
Slide those edges right and left until you can lay the fabric down into a nice fold opposite the selvage edge while keeping the edges lined up together, as shown in the picture above.
Next, I line the fold up with a line on my cutting mat. Some people don't use the mat lines and instead line this fold with their ruler but I find the mat lines to be easy to use and reliable. You can check to ensure your mat is not warped by placing your ruler over it and seeing if the lines all match up. In the picture you can see how the fold at the top is lined along the line.
Now look at the left side edge of the folded piece. If you cut left handed, then whenever I say right you need to substitue left and when I say left substitute right. In this photo you can see that the edges don't line up perfectly and this is often the case. Fabric can stretch on the bolt, it can stretch as it is handled and shipped. And often these edges have not been evenly cut at the fabric shop.
However if the selvage edge is even with the opposite edge or other selvage, and the fabric is wildly out of line on the left edge, you can take a minute to try to minimize that. First, pick up the fabric and stretch it along the bias at several points on one side. That is, hold it at the 45 degree angle points and give it a good tug. Then do the same on the other side. Often this is sufficient to remind those warp and weft threads to get back into their grid. If this does not work, your can either just carry on or you can throw it in the washer. Washing will usually get rid of all the stretch that has been added and bring all the threads back into place. Once you are done, press and fold it again.
If you like to starch your fabrics, this is the best point to pick up the fabric, starch and press it and then fold it back into place. I don't starch my pre-washed fabrics but many people prefer the added stability that the starch adds and adding starch will reduce the tendency of the fabric to stretch once curves have been cut.
Now, making sure that the top fold is still lined up with a line on the mat all the way across the fold, I then line the ruler with the mat lines and overlap the edge a little - enough to ensure that when I cut I will cut fabric along the entire cut.
In this photo you can see how the ruler is lined with all the lines on the mat. Once everything is lined up, place your left hand on the ruler to hold it in place, make sure that no part of your fingers or hand extent over the edge of the ruler even by a tiny bit, and cut along the ruler with your rotary cutter. Always cut away from your body.
If you are making a long cut across a full width of fabric piece, place your left hand close to the selvage end, cut to the point just at the end of your left hand, stop, carefully lift your hand and move it further along the ruler, check to make sure that the fabric has not shifted, hold again and cut, until you get to the end of the fabric. Otherwise, you will find that the pressure of cutting, especially as you move away from your body will push the end of the ruler and your cut will not be straight.
The picture above shows the cut edge and the fabric to be discarded. Now you have a nice straight edge which should also be perpendicular to the top fold - and your fabric will be square with the cut being along the weft threads.
Now you can line your ruler up to cut strips off your fabric. In the picture above you can see the ruler lined up to cut a 2.5" strip. I line the ruler with the straight edge of the fabric, the top fold and, assuming that both of those are still lined with the mat, I also line the ruler up with the mat lines. Cut the strip with the rotary cutter and then you are ready to cut your next strip. Your strips can then be cut into smaller pieces. For smaller pieces you can again line up the strip with the mat and use the approach of lining up all the ruler and mat lines for really precise cuts.
If you are cutting strips from a piece that is cut selvage to selvage, the best practice is to cut with just one fold and the two selvages together for your first truing up of the edge and for all subsequent strips, but I often will fold the piece a second time and work with the fabric 4 layers thick as it is easier to cut a shorter distance. If you do that, be careful to watch that your folds are straight and lined up or you will see V shapes along the edge of a strip, especially near the fold. If that happens, pick up the entire piece of fabric, carefully refold and position it, cut the first edge again and carry on.
Now we can look at cutting out curved pieces. Since these are bias cuts, starting with a good cut for the base piece that is along the warp and weft threads as described above gives you the best chance of having pieces that stretch the least as you use them. This will lead to the nicest sewn curves.
As we are working on the Mod Pop Quilt Along, I am going to use the cutting of quarter circles for this explanation but my tips should help you to cut most any curve. Since we are working from Julie at Distant Pickle's pattern, to respect her rights, I will not be sharing the measurements of the pieces and you can get them from your pattern.
After you have cut your fabric into squares or rectangles, get one of the fabric pieces and one of the templates. You can make a template by tracing the template pattern onto a piece of cardboard and cutting the cardboard out. Look for a piece of cardboard that is sturdy but not too hard to cut smoothly and if you want the template to be thicker consider gluing a few cut pieces of cardboard together. Alternatively you can purchase a template from Julie (go here).
Templates can be slippery on the fabric, whether made from cardboard or acrylic. One way to address that issue is to be aware of this issue and hold the template carefully. It can also help to add, small pieces of non-slip material to the back of the template such as sandpaper, sticky tape, or store-bought non-slip material. A bit of low stick glue will also work nicely and will need to be replaced from time to time. You will see in my pictures that the templates from Julie came with a bit of glue to hold them in place while shipping. I left a bit of it in place to help address the slipping issue.
There are two basic methods to cut the fabric - using a rotary cutter along the template, and using the template to draw a cut line and cutting with scissors.
If you are using your rotary cutter, you can use any size cutter, but if you have a rotary cutter with a blade of smaller circumference it will be easier to use. Place the template on the fabric, position it carefully to ensure that fabric is under it to the outside of the straight edges so your piece of fabric is not short on those straight edges. Hold the template carefully with your left hand, again ensuring that no part of your fingers or hand extend into the path of the blade along the curve. Steadily move the rotary cutter along the curve.
If you are cutting from prints and want to use your clear template to help you "fussy cut", first locate your preferred cutting location, hold the template in place and cut the straight edges. Stop and reposition the template to ensure that it is in the proper place along the straight edges, reposition your hand and cut the curved side. It is not advisable to try to make your way around the entire template in one go as it is really hard to avoid the template shifting a little and thus the resulting cut will be less precise.
If you are comfortable cutting several layers of fabric at once, you should be able to make precise cuts of up to 4 - 6 layers of fabric cutting this way. Just be very careful to watch for shifting of the fabric in the layers as you position the template and cut the fabric. The most precise cuts are obtained if you cut only one or two layers of fabric at time.
An alternative way to cut the curved pieces, and my preferred way, is to use the templates to draw your lines and cut with scissors. First, cut the strips, then squares and/or rectangles with your rotary cutter in the usual way. Then take a single piece of fabric, position your template as explained above for either regular or fussy cutting, and then draw the necessary cutting lines on the fabric. I use a heat sensitive pen but any marking pen or pencil will work. Then cut the curve with sharp scissors, preferably ones reserved for cutting fabric only.
If you are cutting with scissors, you can speed up the process by marking some of the fabrics and then cutting those pieces in a stack with others. As with rotary cutting, as you add more layers, the less precise the cuts become so I generally stick to 4 - 6 layers. Also, when cutting with scissors you will be holding the fabric off the table in your hand. A stack of fabrics will fan out really quickly so keep moving your holding spot along to where you are cutting, checking that the other edges are also still lined up together.
The benefits to cutting with scissors is that you don't have to be standing at your cutting table and instead can be watching TV or visiting with family or friends. The benefits to using the rotary cutter is that the cuts will almost always be more precise. You can try both methods and see what works best for you.
Remember that the pieces you have cut on the bias are easily stretched so handle them as little as possible until they are ready to be sewn.
If when you cut all these pieces you have a nice set of smaller "pie" shaped pieces left over from cutting the "L" shapes, keep them. You can take their measurements and make another proper size "L" shape and use them for another project using drunkard's path quarter circles. A wonderful explanation about how to calculate that template is here where Leila from Sewn explains how.
I also wanted to point out that it is not necessary to cut all the pieces in one sitting. You can cut some of them, sew some of the blocks and then cut some more. I tend to sew quilts in this manner as I really don't like the cutting part so I spread it out.
If you have any questions let me know or if you have your own cutting tips to add, please share them in the comments.