Invisible Thread

No, this is not like the invisible woman.  It's much more useful!

Ok, I guess she's kind of useful... I'm just jealous of the boobs

This stuff is nylon and comes in two shades: clear and smoke (for those darker, more mysterious fabrics).  You can get polyester invisible thread, but I've never used it myself so I can't comment on it's use.

I've only ever used invisible thread for repairs and small parts of dressmaking.  I have been told that when using it in a sewing machine there are three key things to remember:

• Reduce the sewing machine tension
• Only half-fill the bobbin 
• Use the smallest needle possible

For hand-stitching, the small needle thing is just as important - it looks much better after you've finished sewing. This is because the invisible thread is one long fibre; unlike normal cotton/polycotton/whatever threads you usually use.  An easy way of thinking about it is that your usual threads fray at the ends when you cut them - we've all had the burning rage at a thread when it just. won't. go. through. the. needle!  Well, invisible thread won't do that, which means it won't relax and fill the holes your needle makes (no giggling!).

Oh yeeeeea, you sew that buttonhole!

It can be quite odd to get used to, and when hand stitching I'd advise locking the ends of your stitching by using back-stitches, not tying knots.  Although this stuff is super fine, it will still feel lumpy to your fingers if you try and knot it as you would a normal thread.

You can pick up a spool of these for around £2 from somewhere like Hobbycraft, or your local Haberdashery (you can go to non-local one's too, but that just seems like a lot of hassle.  Unless your local one is run by octopuses.  Then I guess go a bit further afield.  It's not that I'm against octopuses, it's just that they don't really know how to sew properly.  Also I'm jealous of them, but that has nothing to do with this!).

Aaaaanyway, hope that was in some way helpful.

Live long and prosper.