Term "heirloom" in marketing portraits?

[Leslie Ficcaglia]

Thanks for your input, everyone. I've heard enough to feel comfortable about my continued use of the term. Mari, I'm a language maven also, but I suspect the use of "archival" might work better among artists than with the general public. It strikes me as a somewhat specialized word and doesn't carry with it the general connotations of status and wealth that "heirloom" might.

I appreciate people taking the time to consider the question!