Sewing with knits
There have been so many fantastic blog posts about sewing with knits lately, that there's really very little to add...so I'll keep this brief (yes, a concept that usually appears foreign to me). However, I want to share some of the things that I've learnt from them and what I've found works for me.
Firstly, I wanted to share my twin needle love - two needles that come off one shank and can be inserted into your machine just like a regular single needle - you only need a spare spool holder to accomodate the second reel of thread - mine slots into a hole in the top of the machine.
Just as you would with a single needle, you need to make sure that the twin needle is the correct type for the fabric underfoot- so when sewing with knits it should be a stretch or jersey ballpoint needle - mine is a Schmetz Stretch Twin. I always lengthen my stitch length to about three when sewing with a twin needle.
When sewing with knits I use a regular polyester thread in the spool holders (I always use polyester for dressmaking as it's stronger and has a tiny bit more give in it) and wooly nylon in the bobbin case. You can wind this easily by hand. The wooly nylon thread has a little more elasticity, is incredibly soft and strong and helps to create happy looking stitches on your knit fabric.
I also use Wooly Nylon thread in the upper looper of my overlocker (I know some people use it on both loopers on their overlockers - I don't, as it's incredibly expensive and using it in just the upper looper, for me, produced the same result as using it in both).
Visible proof that using the right needle, settings and thread for your fabric type can make a huge difference: these two pieces of fabric were run through the machine one after the other with a stretch needle, Wooly Nylon thread, and with the settings adjusted for a knit fabric. The blue fabric on the left is a regular quilting weight cotton - you'll see that the stitches don't sit nicely on the fabric and that it is pulling over and looking generally ugly. The knit fabric on the right looks perfect though, hurrah!
You should know that Wooly Nylon will melt under the heat of an iron and it is not recommended that you iron over the seams at all. However, as I'm not actually capable of making something without ironing it at nearly every stage, I conducted my own experiements and found that it remains perfectly in tact under a brief, but firm press with the temperature of the iron set to 2 (or whatever temperature your iron recommends for wool). I think the theory is that one shouldn't need to iron knit fabrics, so the fact that the Wooly Nylon thread has a low melting point is irrelevant. I completely disagree with this - I think that every fabric, particularly during construction, can benefit from being ironed and would rather risk melting my threads than omitting this stage. Pressing feels almost as intrinsic an element to garment construction as creating the stitches with the sewing machine or overlocker.
Oh and one more thing...Kate asked after my last post about shrinkage - yes, the Patty Young knits do shrink by about 15%, so it's worth buying more fabric than you think you need and always remembering to pre-wash. I don't know whether this is peculiar to Micheal Miller knits or a universal thing with knit fabrics as I always pre-wash fabric for dressmaking and only noted the shrinkage on this occassion because I knew to look out for it.
Finally, I leave you with some knitty links to YouTube videos created by Queen of Knits, Patty Young, that give so much wonderful information about sewing with knits.
Hemming Techniques for Knits 1 - Coverstitch (possibly the least useful as it's only really relevant if you have a coverstitch machine...but worth watching for the geeky fun of it and for adding a coverstitch machine to the long wish-list of sewing paraphernalia)
Hemming Techniques for Knits 2 - Rolled Hem (this shows you how to create a rolled hem with knits using an overlocker...so again, only relevant if you own an overlocker).
Hemming Techniques for Knits 3 - Lettuce Edge (again, for overlocker owners only).
Hemming Techniques for Knits 4 - Faux Coverstitch (Something for sewing machine owners - this shows you how to recreate on your sewing machine something resembling the finish that the coverstitch machine produces).
Hemming Techniques for Knits 5 - Zig Zag (Again, tips for sewing machine users sewing with knits).