Here is a picture of a loom:
Yes, it’s a matchbox.
This was the very first type of loom I ever used, because when you work with seed-beads everything is on a small scale.
But what is the matchbox doing?
Well, it’s holding the warp threads in place and under tension, so that the person in the picture (that’s not my hand) can use a needle to pass the weft thread over and under the warp threads.
This kind of loom is basically a frame for holding the warp.
Of course, most looms do a lot more than this; importantly they allow you to sandwich the weft between two sets of warp threads, rather than manually feeding the weft over and under each one. This makes weaving faster.
The loom achieves this by lifting one group of warp threads to make a gap for you to pass the weft through.
In this image, you can see that the shuttle holding the weft thread is actually sitting in the gap between two sets of warp threads (that gap is called a shed). When that gap closes, the weft thread ends up under the top group of weft and over the bottom group, giving you the over, under structure.
Another thing the loom does to help out, is to press the weft into place – this is called beating – which keeps the weft tidy and determining how closely the weft threads are packed into the warp.
How the loom achieves all this I’ll cover in another post, but before we finish, take a look at the image above and how the woven cloth wraps around the front of the loom. This is one more helpful thing, because that cloth beam, as it’s sometimes called, stores the cloth and keeps it out of harm’s way while you continue weaving.