Attributes by manufacturer?

I'm using ZenCart 1.3.9h with EasyPopulate and everything is working great, but I have not figured out if there is a way to add attributes based on manufacturer.

Any way to do this that I'm simply overlooking something very basic?

Attributes are by product

Not sure what you mean with by manufacturer

I have several vendors that I purchase my items from...

Typically, attributes vary from vendor to vendor (aka manufacturers).
So, Vendor A only sells sizes XS, S, M, L...
Vendor B sells L and XL.

Is there an easy way to filter by vendor/manufacturer, and apply the same attributes to Vendor A ONLY? (Now I have to copy attributes one item at a time...)

Let me know if you can think of something, and thanks in advance!

Restructure your cats by mfg and use linking to get them in other cats

https://www.zen-cart.com/tutorials/index.php?article=216