Best recycled paper product.....what could it be?

I took a training a couple of days ago, and really liked the recycled cardboard binder for the training materials.

It's not bleached, it touched rough on surface, it got slightly fluffy easily when in contact with table or other objects.

Yes again, like Whole Foods paper bag, it has an apparent quality of recycled product - not as good as new one.

That's exactly what I like with this binder. This is for training material. I don't care if the edges get bent or the surface get fluffy. As long as it can keep the papers together, I have no complaints at all.

According to my "recycling-is-not-alchemy" theory, contaminated post-consumer paper shouldn't be able to produce something of high quality unless you add more virgin material or more energy input to offset the bad quality of the feedstock.
Based on that, this binder could look like above. Ratio of post-consumer product in feedstock is probably high, energy or chemical input required for process is low, but the product is not as good as new product. (it's totally acceptable in this situation) I doubt it might not be recycled again. Maybe egg case?

On the other hand, if you try to make copy paper from recycled paper, it could be like this.

This is an unproven theory. I identified the maker for the binder and asked about the material, but the answer was "We know it's made of recycled paper, but we are not sure about the details."

I will investigate more even though not much information is available out there.

I really think the information will help to determine what to make out of recycled paper and what not to, to make paper recycling truly environmentally beneficial.