Instead, I am a big fan of the free program Inkscape, which you can get for unix/linux and also mac with the X server, and probably Windows, if you're into that kind of thing. Many journals would be unhappy with such an image, and in any case it would look bad and make your pdf filesize huge.

I would discourage the method of drawing them by hand and importing them via scanner etc. Using it, I can produce SVGs (as evidenced by some nLab pages:, , and some others) as well as PDFs, PNGs, and so forth. I'll not post code here (ask by email or on if you want). I've recently had occasion to draw a few knots and links using TikZ and have quite a workable system. This is a follow-up to Niels' answer, namely to use TikZ. The package was inspired by a question on TeX-SX and now has its own tag tikz-knots. And here's a short blog post I wrote explaining the variety of methods, and a slightly more detailed tutorial. For drawing braids, there's the braids package. The hobby package also contains some useful code for drawing knots. It is released as part of the spath3 library. It is already in MikTeX (according to CTAN), TeXLive might have to wait until TL2013 has been released. Update : I've now uploaded a TikZ library to CTAN expressly for the purpose of drawing knots. Here's some example code and rendering, for more see the package documentation.

(This isn't a replacement for the original knots package, that is still being maintained.) Update : I've now uploaded an extension to my spath3 package which provides yet another way to draw knots and links using TikZ.

How to use inkscape .tex output