Using aged domains for back linking ?

This is black hat for sure

[Future]

I recently came across a SEO person who do backlinking on aged domains for there clients.

As far as i have read various threads here, this can be considered blackhat or wrong way to build links.

can anyone please be more precise if using aged domains is helpful ?

using aged domains to develop directory, blog etc and then sending a link from same to clients site.

[theentry]

If it's a regular backlink then I won't consider it as a black hat method.
And a backlink from an aged domain worths more then a link from a new domain. Of course that's not only one factor.. there are other factors like the niche/topic of the site, the position of the link (header,sidebar,footer)..