primary form

{{Notability|date=December 2019}}

Primary form is used in surface metrology to refer to the over-all shape of a surface which can be measured quantitatively.{{cite web |title=A Guide to the Difference Between Primary Form, Roughness, and Fractality of Surfaces |url=https://www.azom.com/article.aspx?ArticleID=17534 |website=AZoM.com |language=en |date=27 January 2019}}