What Matters When
Often when I talk to people about sewing, there are questions about some of the basic concepts, such as bobbins, stitches, thread, needles, etc., so I thought I’d write about some situations where each of these matter.
The first one, bobbins, applies to every situation in which your machine is being used. It is very important to have the correct bobbins in your machine, or you could throw off the timing of your machine (and then it will need servicing)! Your manual will tell you which size you need (they come in “classes” - ie: Class 15, Class 66, Class 15J, etc.), or often the information will turn up in an internet search. A loose rule of thumb is that regular modern machines standardly take a Class 15 unless they are an embroidery machine, but DO YOUR RESEARCH FIRST! A lot of time (and money) will be lost in having it serviced. Some machines also care if the bobbin is plastic or metal, but others don’t, and if your bobbin has a casing, this too is unique to each machine and cannot be substituted.
(from left to right: nylon upholstery thread, variegated embroidery thread, cotton thread, topstitching thread, all-purpose polyester thread, invisible thread)
Thread type actually matters less than most people think. Oftentimes, the way something is sewn is what makes the difference in the finished result being stronger, stretchier, etc., not the thread type. In about 99% of standard sewing projects, all-purpose thread will work. Common exceptions are if you are making something that will go in the microwave (in which case, everything in your project should be 100% cotton, including the thread), and if you are sewing an outdoor project, in which case you might want to use a nylon or UV resistant thread to help you project withstand the elements.
Waxed thread (or hand quilting thread) should only be used when sewing by hand. Putting this kind of thread through your machine will eventually gum it up.
Clear thread is used for projects that have too many colors to match, or where you want it to show up as little as possible. (note: it has a lot of body and can be tricky to work with).
Elastic thread (usually used for shirring) only goes in the bobbin and is wound there by hand.
Needles do matter a bit more in many cases. Not so much for the machine as for the fabric being used (though sometimes the machine type matters too. Again, read your manual!). The type of needle depends on the fabric you’re sewing with. A general rule of thumb is the higher the number (90/14 vs a 70/10) the stronger the needle. You would need a higher number for sewing with denim (or multiple layers, like a quilted project) as opposed to chiffon. If you choose too low a number for a heavy fabric, the needle is more likely to break, whereas if you choose too high a number for a lightweight fabric, the stitching tension might be off.
Another time another needle type is needed is when working with knit fabric. Specific needles are made for this - they will say “stretch” or “jersey” on the package - but while using the appropriate needle helps with knits (and prevents runs in the fabric), the biggest game changer is using a stretch stitch with them. Most machines have a stretch stitch on them - it will probably look like a lightening bolt. If your machine doesn’t, a small zigzag stitch will give the same results.
Most machine needles are universal - you do not have to use Singer brand needles if you have a Singer machine. The opposite is also true: you can use Singer needles (or any other brand) in most standard sewing machines.
Last note on needles - the way they are inserted into the machine matters a lot! Most needles for standard sewing machines have a flat back and a rounded front on the shank. If they are inserted backwards, with the flat side not to the back, the machine will run but it will not stitch correctly.
