Thread Weight -When to use 40 versus 50
 

I am a newbie to machine quilting and I am overwhelmed by all the choices of threads and weights. What thread weight should I be using for my machine piecing? domestic machine quilting? and for sewing on the binding?

Thank you in advance for your help :)

It really does depend on your machine. My older Bernina doesn't like when I use less expensive thread so I just recently started using Aurifil 50 for piecing, quilting and machine stitching binding.

I use 50wt for piecing & sewing on the binding. You could use either a 40 or 50wt for the quilting. 40wt is thicker & shows up a bit more so it just depends on whether you want that or not.

Also, if you switch to 40wt thread, be sure to also switch your needle size accordingly. Pretty much all manufacturers tell you the recommended needle size for each weight. I know for Aurifil, 50/2 thread can take a 70/10 or an 80/12 needle. Aurifil 40/2 takes an 80/12 needle. Aurifil 28/2 (the heaviest thread you can run through a machine) takes a 90/14 needle.

Thread weight is a personal choice and often depends on the 'look' you are after. The only time I use 40 weight is when I want to really emphasize the quilting stitches. I often use 60 or 70 for quilting as I really like to see the texture rather than the quilting thread. I use 60 for piecing.
If you do decide to change the weight of thread you use for piecing, remember to check your seam allowance, as thread thickness may affect it:
http://www.quiltingboard.com/tutoria...ce-t89997.html
I attach almost all my bindings by machine and just use whatever weight & color matches the binding best.
Remember to use an appropriate needle size to match your thread weight.

I use 50 weight for everything----keeps it simple and my Juki runs great with it.

An additional consideration....If your quilting design involves areas where you are traveling over the same area several times, I.e. Flower centers or backtracking, a thinner thread will lessen the thread build up if it's a concern.

I use 50/3 for both. I am thinking about moving to a 60 weight for the bobbin for piecing. You want to stay away from thick threads for piecing as the thickness of the thread makes a difference in the final block. It also distorts the pressing.

If you want your FMQ to blend, use a 50 weight in a color to match. If you want the stitches to show use either a contrasting color or a thicker thread.

A lot depends on the machine too. Some are persnickety. Mine WILL NOT use Coats and Clark dual duty but it likes Coats and Clark Star brand. Go figure.

Thank you everyone for the useful information! I didn't know that heavier wt thread could distort my piecing:) I want my stitching to blend, so I'm going to use 50 wt for everything. I will also pay attention to my needle size :)
Thank you!

I love Superior Threads "Masterpiece" 60 wt. thread for piecing in both the top and bobbin. You order it online. It comes in large cones. I use either beige, grey or black thread for piecing. I also like their So Fine 40wt thread for quilting.

You cannot look only at the wt of the thread. Regular cotton thread is 50wt 3-ply. I find that this 3-ply thread takes up too much of the seam allowance. I get more accurate piecing by using Aurifil 50wt 2-ply thread. In addition to thread weight, you must also look at plys and also at composition of the thread. I prefer cotton thread for piecing because it "grabs" better than slick polyester threads. Aurifil is a good brand because the thread is very smooth, leaving less lint in your machine than many other cotton threads.

I have used regular 50wt 3-ply thread to quilt with. It is fine as long as your quilting lines are a moderate distance apart. If you do a lot of close quilting with this thread, you will find that this thread will stiffen your quilt quite a bit. For quilting I prefer a polyester thread to cotton for several reasons -- it is stronger, it does not dry rot over time, and it will not stiffen a quilt as much as cotton thread. My favorite is Glide thread, although Sigma from metroemb.com is supposed to be very similar (and much cheaper, especially if purchased during one of their 50% off sales). For a cotton thread that will blend for quilting, I again like Aurifil 50wt 2-ply. These 2 threads do not make my quilt stiff even if I go hog-wild and quilt in little loops all over the surface. :eek:

For my initial years of quilting, I have to admit that thread did not seem important to me and I used mostly 50wt 3-ply. In the last few years, however, I have realized that thread quality does make a difference to me. I think this is a common progression in quilters.