You can get beading thread in different sizes, colours, waxed (also called pre-waxed) and un-waxed. Waxed thread is less likely to break and fray. It also glides through beads much more easily. You can also use beeswax to thread your own threads.
Find out about the applications, sizes and types of bead threads.
Silk, Linen, Cotton, Leather thongs, Hemp are amongst the most common and popular of natural stringing materials. Even though hemp can be used for beading, it is generally reserved for chunkier designs, can be knotted and braided to great effect (e.g. as in macrame).
Silk and Linen threads are certainly not as strong as synthetic threads but they remain popular and have specific purposes for which they are traditionally and admirably suitable. These natural beading threads are available in different colours and sizes.
Silk threads are used mostly for pearl, small mineral, or gem beads ~ especially those with small holes. In fact, silk thread is the traditional thread for stringing pearl. It still remains very popular for stinging pearls as the other stringing materials can hurt the pearls. But be aware that silk threads then to fray and stretch. And silk will break down within 3-5 years hence anything strung with silk threads have to be restrung.
However, it is not advisable to use silk thread with glass beads.
Silk threads can come on cards, sometimes with a useful integral needle. This is also described as "pre-threaded" which you may come across when you are looking to buy. You can also buy them in spools.
Some known brands of silk threads are:
Nylon, polyester, bonded nylon threads are all synthetic beading threads.
Synthetic threads are the modern way of bead stringing as they do not fray nor stretch as much. Polyester thread is usually used for beadwork that requires a needle. Give yourself plenty of extra thread if you intend to weave or knot with these threads.
Some well known synthetic and nylon threads are: