  The interstellar medium is highly structured, presenting a range of
morphologies across spatial scales. The large data sets resulting from
observational surveys and state-of-the-art simulations studying these
hierarchical structures means that identification and classification must be
done in an automated fashion to be efficient. Here we present RJ-plots, an
improved version of the automated morphological classification technique
J-plots developed by Jaffa et al. (2018). This method allows clear distinctions
between quasi-circular/elongated structures and centrally over/under-dense
structures. We use the recent morphological SEDIGISM catalogue of Neralwar et
al. (2022) to show the improvement in classification resulting from RJ-plots,
especially for ring-like and concentrated cloud types. We also find a strong
correlation between the central concentration of a structure and its star
formation efficiency and dense gas fraction, as well as a lack of correlation
with elongation. Furthermore, we use the accreting filament simulations of
Clarke et al. (2020) to highlight a multi-scale application of RJ-plots,
finding that while spherical structures become more common at smaller scales
they are never the dominant structure down to $r\sim0.03$ pc.
