From Becky...
For years I have advised the students in myclasses to use cotton thread unless they have reason to choose a thread made from another fiber. That is still my firm recommendation. I believe that cotton thread used with cotton fabric is the best choice from a conservation standpoint. But, and this is a big BUT, I am re-thinking the reasoning that I have always used to support my views.
Bob Purcell at Superior Threads knows a lot more about thread than I do. He is doing a fine job of educating quilters about thread. He recently wrote about polyester thread (under Education) in the May Superior Threads Newsletter. What he wrote is food for thought.
I do know that new polyester threads are much better than the ones that were available when I began quilting 25 years ago. Polyester is strong and does not make as much lint in your sewing machine. It is available in an incredible range of colors and weights. Lots of big names in our industry love and use it.
If I were a garment maker I would probably use polyester thread all the time. If I made quilts that were going to take a lot of wear and be washed a lot, I might consider switching to polyester. Hand appliqued quilts don’t usually fall into that category.
Polyester thread often has a sheen that makes it more visible. That works well for machine quilters who want that the stitches to show up more. If I wanted my machine quilting stitches to be more prominent, I would consider using polyester thread.
For invisible hand applique stitches, I prefer a thread without a sheen because the stitches hide in the fabric better. I have been doing some applique with more visible stitches (see Applique Outside the Lines) and, so far, I prefer a matte finish on those threads as well. If I run into an area where I want some shine, I’ll consider using polyester thread.
I do have concerns about the possible break-down of polyester over the long term. We know that cotton lasts if it is stored correctly. Polyester fibers may outlive us all by centuries, but it hasn’t been around long enough to know that for sure. In most areas of my life I am a true early-adopting techie but when it comes to quilting I make more conservative choices.
I cannot see a reason in my own work to use polyester thread at this time - but maybe you see a reason to use it in your quilts. My advice to you would be to choose the thread that, based on what you want it to do, works best for you.
FYI - As many of you know, we LOVE and use Superior’s Masterpiece cotton thread. The 'Frosted Donut' and the other bobbins on our site are filled with Masterpiece in colors that Linda and I selected. We both hand applique, piece, and do a lot of machine quilting with Masterpiece. It is our go-to thread.
ABOUT SILK THREAD - Some of you will notice that I didn’t mention silk thread above. Silk is harder to keep on your needle as you stitch, it is a bit harder to find in the shops in a wide range of colors, and (the last time I checked) it was more expensive. When there is so much good cotton thread available that does the job so well, why use silk?
About those numbers...
If you look on a spool of thread there is often a number. This number indicates the fineness of the thread. There is no universal standard that this number corresponds to. Each manufacturer assigns numbers based on the particular threads they offer.
Thicker thread is more visible in hand applique. Thicker thread takes up more space in a pieced seam than a finer thread does. We generally prefer to use finer threads for more invisible stitches and flatter seams. When using finer thread in machine piecing you will need to use a slightly shorter than normal stitch length.
To summarize, use the weight number printed on the spool as a general indicator of a thread's fineness. Rely on your eyes and the feel of the thread to help you decide which thread is best for your project.
