Uh. I see this thread just now, and here we are, at the deep end again
You can make your own book cloth out of any thinnish, tight woven cloth. Cotton is popular for its uniformity and possibility for a tight weave. Tight weave is desired to keep paste from squirting through the weave when you glue it. I'd steer away from unnatural and shiny textile unless (see, even here
it depends applies) you're covering your book covers (boards) with paper first and then make a 'drum' covering = gluing only the folded down edges on the inside of fabric.
Thickness matters because of the corners. With leather we can pare down at the corners. With fabric not so.
I haven't watched the videos, but here's how I go about making book cloth out of any suitable cloth;
Figure out the measurements of the area that needs to be covered.
Cut a piece of tough, thin, very flexible paper to measurements bigger than your to be covered area (minimum being the height of covers + turn-ins top and bottom, width of covers + spine + joints + turn ins). There's no maximum size, except that at some point it becomes too difficult to handle.
Japanese handmade papers are popular for this purpose (no grain direction since hand made, grain direction has an effect on stretching and shrinking of paper when moisture of the paste - coming up soon - is added).
Then cut a piece of your selected fabric with edges about an inch more in every direction than that of your paper.
You're going to glue the paper and fabric together with starch paste, which you will cook yourself, like
here (lots of useful info in the comments too). This is how;
Find a smooth, non-porous surface to work on that is bigger than your cut piece of fabric. This can be a metal counter top, a marble slab or a slab of thick glass.
Lightly spray your piece of fabric with water to make it a bit moist. Place your lining paper (the Japanese handmade paper) in the middle of the marble slab or similar smooth surface, and apply paste, brushing from the middle to the edges and on purpose let your brush run a bit on the marble slab as well, for 1 inch or more outside the paper edges. Try to get a thin, even layer of paste with as few brush strokes as possible (multiple brush strokes over the same spot of paper might stretch the paper).
Then place your fabric over the paper, with the good side up, 'back side' down on the paper, with as even 1 inch edges overlapping the paper as possible, trying to work from one corner diagonally to the other, smoothing out any air bubbles as you go. A wooden ruler is the traditional tool for this, but creativity is always welcome and encouraged.
As you're doing this, you're also pasting the fabric taut over the paper, onto the smooth slab of non porous material. Leave to dry. When dry, you can lift your DIY bookbinding cloth off the smooth slab quite effortlessly.
Good luck!
And for the next bookbinding question, if you want, add Nina anywhere in the text, and it'll show up in my inbox and I'll see it sooner.