Are Arborvitae every grown from seed and if so, how can I locate and/or but seeds

There's this which I found doing a search... and I might a have few seeds stashed around here myself somewhere.... I will check...

Did you mean the narrow ones?

I'm positive that the narrow variety used around here for hedges called 'Emeral Green' is only from cuttings - it's also known as 'Smaragd'.

But the other narrow arborvitae Thuja occidentale might possibly work from seeds, although its fairly certain to be grown from cutting many times.

That American arborvitae has a nice foliage with a large form.