ok, i looked into it more.

i made measurements using pieces of paper taped together instead of folders, if anyone is interested in them.

but, it seems like mats will move around and lose shape too much if they don't have a rubber backing, even thick sisal house rugs cut down to shape.

i tried my best to find an affordable solution, but i ended up going with cocomats.com.

here're some notes on what i researched:

daniel’s cost less, $120, but possibly thinner and not as durable.
heelpad: vinyl
backing: vinyl
there’s no confirmation of whether or not the rubber backing is natural or synthetic.
Daneil's Sisal Floor Mats


the hemp rugs, i tested one, it slides and moves around too easily due to being light and having no backing.


cocomats.com are pretty pricey, $280, but seems like they would last 10 years or more.
heel pad: natural rubber
backing: natural rubber
the heelpad is thick too, not a cheap vinyl which does fall off on cheaper mats.
binding: vinyl
i asked if i could send in a natural leather, but they said all of their equipment is set up for the vinyl binding, and it is a very good solid binding. and without binding they would fray and fall apart.
glue: silicone
they searched as best they could for glues and use a silicone glue which does not offgas. as far as i've researched, silicone is a relatively natural substance, coming from silica and sand, but requires fossil fuel chemicals to make, but supposedly does break down in sun and soil.

they're made in the US by a family company, and the videos of them talking about it really helped sell me on them.

they said coco is the most durable natural material compared to sisal and seagrass, if buying for a daily driver.

i still think it's ridiculous to pay $280 for something you'll just be stepping on, but i couldn't justify buying such large pieces of synthetic material that could not be disposed of when they're done, even if they cost only $30 or $55 like the cheap universal ones cost.