Sleeve focus thread

[Koen G]

I had also thought it might look like fur as well, like the royal ermine lined robe type of thing?

That's what I would suggest for the neck lines of the VM dresses. They just lack the detail to say whether it's fur or not.
All images I used above are from the BNF fr. 357 MS, also the guy in red.

On polka dots I'd say again that the VM image is simplified. These rich fabrics were often patterned, making them appear even more expensive.
Here's just an example I pulled from my earlier blog post (ignore the arrows), look at the pattern on the left man's sleeve.